Seza Goker | Middle East Technical University (original) (raw)
Papers by Seza Goker
New Journal of Chemistry
A sensing platform for catechol detection incorporating triple key materials based on SiNPs, D–A–... more A sensing platform for catechol detection incorporating triple key materials based on SiNPs, D–A–D type conducting polymer, and MWCNTs.
![Research paper thumbnail of Effect of thiophene, 3-hexylthiophene, selenophene, and Thieno[3,2-b]thiophene spacers on OPV device performance of novel 2,1,3-benzothiadiazole based alternating copolymers](https://attachments.academia-assets.com/107047277/thumbnails/1.jpg)
](Journal of Electroanalytical Chemistry, 2021
Four novel alternating copolymers bearing 5-fluoro-6-((2-octyldodecyl)oxy)benzo[c][1,2,5]thiadiaz... more Four novel alternating copolymers bearing 5-fluoro-6-((2-octyldodecyl)oxy)benzo[c][1,2,5]thiadiazole as a strong acceptor unit and 9,9-dioctylfluorene as a strong donor unit with bridging units namely, thienothiophene, selenophene, 3-hexylthiophene, and thiophene were designed and synthesized. The polymers were characterized via 1 H NMR spectroscopy, and weight average molecular weights were reported via gel permeation chromatography (GPC). For synthesized novel polymers, the bulk heterojunction solar cells were constructed. Besides, the effects of bridging units on electronic, optical, photovoltaic, and morphological properties were investigated. Among the polymers, the thienothiophene containing polymer P1 exhibited the highest PCE as 4.25% under the illumination of AM 1.5 G with 100 mW/cm 2 .
Journal of The Electrochemical Society, 2021
Four novel benzo[c][1,2,5]thiadiazole comprising monomers namely 5-fluoro-6-((2-octyldodecyl)oxy)... more Four novel benzo[c][1,2,5]thiadiazole comprising monomers namely 5-fluoro-6-((2-octyldodecyl)oxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole (TBTT), 5-fluoro-4,7-bis(4-hexylthiophen-2-yl)-6-((2-octyldodecyl)oxy)benzo[c][1,2,5]thiadiazole (HTBTHT), 5-fluoro-4,7-di(furan-2-yl)-6-((2-octyldodecyl)oxy)benzo- [c][1,2,5]thiadiazole (FBTF), and 5-fluoro-6-((2-octyldodecyl)oxy)-4,7-bis(thieno[3,2-b]thiophen-2-yl)benzo[c][1,2,5]thiadiazole (TTBTTT) were designed, and synthesized successfully via Stille polycondensation reaction. The structural characterizations of the monomers were performed by 1H and 13C NMR spectroscopy and High Resolution Mass Spectroscopy (HRMS). The monomers were then electropolymerized in a three electrode cell system via cyclic voltammetry. The electrochemical, and spectroelectrochemical characterization of the polymers were reported in detail. Besides, theoretical calculations were performed to elucidate observed experimental properties. According to the cyclic ...
![Research paper thumbnail of The impact of [1,2,5]chalcogenazolo[3,4‐f]‐benzo[1,2,3]triazole structure on the optoelectronic properties of conjugated polymers](https://attachments.academia-assets.com/107047276/thumbnails/1.jpg)
](Journal of Polymer Science, 2020
Two novel conjugated near‐infrared (NIR) absorbing donor–acceptor type copolymers comprising benz... more Two novel conjugated near‐infrared (NIR) absorbing donor–acceptor type copolymers comprising benzodithiophene as the donor and [1,2,5]chalcogenazolo[3,4‐f]‐benzo[1,2,3]triazole derivatives as the acceptors, spaced with thiophene as the π‐bridge, were designed and synthesized via Stille polycondensation reaction. The effect of acceptor strength on optoelectronic properties was targeted and investigated. Branched alkyl chains (the extended 2‐octyl‐1‐dodecyl alkyl chain; C8C12) were introduced to 5H‐[1,2,3]triazolo[4′,5′:4,5]benzo[1,2‐c][1,2,5]thiadiazole and 5H‐[1,2,3]triazolo[4′,5′:4,5]benzo[1,2‐c][1,2,5]selenadiazole for enhanced solubility of polymers which ease the processability hence device constructions. The strongly electron‐withdrawing units lead to a substantial change in the absorption properties via promotion of the intramolecular charge transfer band alongside the π–π* transition. The resultant soluble polymers were characterized via cyclic voltammetry to determine highe...
Journal of Polymer Science Part A: Polymer Chemistry, 2019
ABSTRACTPresent work displays the preparation of an electrochemical biosensor using a conjugated ... more ABSTRACTPresent work displays the preparation of an electrochemical biosensor using a conjugated polymer and laccase enzyme for catechol quantification in samples. The biosensing system is based on an enzyme immobilization on polymer modified graphite transducer surface. For that purpose, a random conjugated polymer, thienothiophene‐benzoxadiazole‐alt‐benzodithiophene (BOTT), was coated onto a graphite electrode surface via drop casting method followed by immobilization of a biomolecule (laccase) for sensing experiments. Herein, for the first time, we proposed a BOTT polymer as an inexpensive and effective way to fabricate highly sensitive and fast response biosensors. The proposed sensing system possessed superior properties with 0.38 μM limit of detection and 110.81 μA mM−1 sensitivity. Furthermore, cyclic voltammetry and scanning electron microscopy techniques were used to examine the surface modifications. The proposed system could be useful for many future studies for catechol ...
New Journal of Chemistry, 2019
A novel sensing platform based on a newly designed and synthesized polymer, poly[(E)-6-methyl-6′-... more A novel sensing platform based on a newly designed and synthesized polymer, poly[(E)-6-methyl-6′-(10-methylanthracen-9-yl)-1,1′-diundecyl-[3,3′-biindolinylidene]-2,2′-dione] (namely PIIDAnth), was fabricated and explored as a glucose amperometric biosensor.
![Research paper thumbnail of Tuning molecular energy levels and band gap of two-dimensional benzo[1,2-b:4,5-b′] dithiophene and quinoxaline bearing polymers](https://attachments.academia-assets.com/107047272/thumbnails/1.jpg)
](Journal of Electroanalytical Chemistry, 2019
Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2... more Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2) were synthesized and characterized where 4,8-bis[5-(2-ethylhexyl) thiophen-2-yl] benzo[1,2-b:4,5-b'] dithiophene (BDT) was used as the donor unit. 2,3-Bis(3,4-bis(octyloxy)phenyl)-5,8-dibromoquinoxaline was used as the acceptor moiety and selenophene and furan were utilized as π bridges. Optoelectronic properties of the polymers were examined by electrochemical and spectroelectrochemical characterizations. In cyclic voltammetry (CV) studies, both polymers were found to be ambipolar. In anodic region, oxidation potentials were observed as 1.45 V and 1.15 V for P1 and P2 respectively, while reduction potentials were 0.65 V and 0.92 V. In cathodic region, redox potentials were found to be −1.36 V/−1.32 V and −2.0 V/−1.51 V for P1 and −1.45 V/ −1.05 V and −2.15 V/−1.45 V for P2. Both polymers showed good solubility in common solvents. The synthesized polymers were used as photoactive layers in solar cell devices.
In this study, two donor-acceptor (D-A) type conjugated polymers namely PQSeCz and PQSeFl were de... more In this study, two donor-acceptor (D-A) type conjugated polymers namely PQSeCz and PQSeFl were designed and synthesized. Selenophene was incorporated as a π -bridge, quinoxaline as an acceptor unit while carbazole and fluorene were used as the donor units. Polymers were synthesized via palladium catalyzed Suzuki polymerization reaction. All molecules were characterized by 1H and 13C NMR Spectroscopy. The weight and number average molecular weights of the two polymers were determined by gel permeation chromatography (GPC). Electrochemical and spectroelectrochemical characterizations of the polymers were performed to investigate their optoelectronic properties. Oxidation potentials were 1.15 V/ 0.82 V and 1.11 V/ 0.82 V for PQSeCz and PQSeFl respectively, while reduction potentials were -1.26 V /-1.14 V and -1.48 V/ -1.23 V, respectively. In the visible region, maximum absorption wavelengths for the two polymers were 551 nm and 560 nm, respectively. Optical band gaps (Egop) were fo...
![Research paper thumbnail of Random copolymers of 1,2,3-benzotriazole and alkoxy-modified naptho[2,3-b:3,4-b′]dithiophene: Syntheses, characterization and optoelectronic properties](https://attachments.academia-assets.com/107047269/thumbnails/1.jpg)
](Journal of Electroanalytical Chemistry, 2017
Naphthodithiophene is a thiophene fused naphthalene with a rigid and planar structure with extend... more Naphthodithiophene is a thiophene fused naphthalene with a rigid and planar structure with extended π-conjugation system and due its electron rich nature it has been recently employed in donor-acceptor type conducting polymers. In this study, alkoxy functionalized naphthodithiophene bearing two new random copolymers namely poly4-(5″-(5,6-bis(dodecyloxy)naphtho[2,1-b:3,4-b′]dithiophen-2-yl)-[2,2′:5′,2″-terthiophen]-5-yl)-2-dodecyl-7-(thiophen-2-yl)-2H-benzo[d] [1,2,3]triazole (P1) and poly4-(5″″-(5,6-bis(dodecyloxy)naphtho[2,1-b:3,4-b′]dithiophen-2-yl)-[2,2′:5′,2″:5″,2″′:5″′,2″″-quinquethiophen]-5-yl)-2-dodecyl-7-(thiophen-2-yl)-2H-benzo[d] [1,2,3]triazole (P2) were synthesized via Stille coupling reaction in order to monitor the effect of thiophene and bithiophene bridge units on electrochemical and optical properties of the corresponding polymers. As the acceptor moiety in the polymer backbone electron deficient benzotriazole moiety was used. Thiophene and bithiophene units were used as π-linkers to enhance electron delocalization through polymer chain. Via alkoxy modification, synthesized polymers were highly soluble in common solvents like THF, chloroform, chlorobenzene. Altering π bridge from thiophene bridge to bithiophene, kinetic properties of the polymers were improved. Electrochemical studies revealed that while P1 has only p-dopable nature, P2 has ambipolar character. Change of π-bridge from thiophene to bithiophene has affected the optoelectronic properties of the polymers in a favorable manner for different application areas. The polymers exhibited low lying highest occupied molecular orbital (−5.40 eV for P1 and −5.30 eV for P2) and moderate band gaps which are 2.05 eV and 2.02 eV for P1 and P2, respectively.
Macromolecular Chemistry and Physics, 2017
Two low band gap triphenylamine based random copolymers are synthesized via Pd‐catalyzed Stille p... more Two low band gap triphenylamine based random copolymers are synthesized via Pd‐catalyzed Stille polycondensation reaction to investigate the role of molecular weight on device performance and optoelectronic properties. 1H NMR spectroscopy, UV−vis absorption spectroscopy, cyclic voltammetry, and gel permeation chromatography (GPC) are used for characterization of polymers. The polymerization conditions are optimized to achieve high molecular weight polymers with enhanced optoelectronic properties. PBTP1 reveals broad absorption in the wavelength range of 300–670 nm whereas PBTP2 has absorption in the wavelength range of 300–660 nm. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels are calculated as −5.43 and −3.20 eV for PBTP1 and −5.33 and −3.02 eV for PBTP2. The photovoltaic device containing donor PBTP1 and acceptor PCBM[70] in 1:3 weight ratio reveals the highest power conversion efficiency of 2.27%, with Voc of 0.63 V, Jsc of ...
New Journal of Chemistry, 2016
Influence of spacers on the optoelectronic properties of polymers.
Journal of Macromolecular Science, Part A, 2016
ABSTRACT Three novel donor-acceptor-donor type random copolymers based on benzothiadiazole (BTh) ... more ABSTRACT Three novel donor-acceptor-donor type random copolymers based on benzothiadiazole (BTh) and benzoselenadiazole (BSe) were synthesized via Pd (0) catalyzed Suzuki polycondensation reaction. The two acceptor units were coupled with electron rich moieties which are carbazole (CZ), fluorene (FL) and silafluorene (SiFL). Monomers were characterized using 1H and 13C-NMR spectroscopy. The number and weight average molecular weights of the polymers were calculated using gel permeation chromatography (GPC). All three polymers were electrochemically and spectroelectrochemically characterized. PBThBSeCZ, PBThBSeFL and PBThBSeSiFL showed only p-dopable character and their doping/dedoping potentials were determined as 1.4 V/1.2 V, 1.53 V/1.27 V and 1.8 V/1.3 V, respectively. Corresponding HOMO energy levels were calculated as −5.85 eV, −6.05 eV and −6.15 eV whereas LUMO energy levels were found to be −3.67 eV, −3.84 eV and −3.77 eV, respectively. PBThBSeCZ had lower HOMO level and band gap than PBThBSeFL and PBThBSeSiFL due to its increased electron donating capability of nitrogen atom in carbazole unit.
Journal of Polymer Science Part A: Polymer Chemistry, 2016
ABSTRACTFour new 2,1,3‐benzooxadiazole‐based donor–acceptor conjugated polymers, namely poly{9‐(9... more ABSTRACTFour new 2,1,3‐benzooxadiazole‐based donor–acceptor conjugated polymers, namely poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSC), poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFC), poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSFL), and poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFFL), were synthesized via Stille polycondensation reaction. All polymers were found to be soluble in common organic solvents such as chloroform, tetrahydrofuran, and chlorobenzene. Their structures were verified by 1H‐NMR and the molecular weights were determined by gel permeation chromatography (GPC). The polymer films exhibited broad absorption bands. Among all polymers, photovoltaic cells based on the device structure of ITO/PEDOT:PSS/PSBSC:PC71BM(1:3, w/...
Journal of Electroanalytical Chemistry, 2015
Synthetic Metals, 2014
Benzooxadiazole containing three monomers; 5,6-bis(octyloxy)-4,7-bis(4-hexylthiophen-2-yl)-2,1,3-... more Benzooxadiazole containing three monomers; 5,6-bis(octyloxy)-4,7-bis(4-hexylthiophen-2-yl)-2,1,3-benzoxadiazole (BOHT), 5,6-bis(octyloxy)-4,7-di-2-thienyl-2,1,3-benzoxadiazole (BODT) and 5,6-bis(octyloxy)-4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,1,3-benzoxadiazole (BODHT) were synthesized via Stille coupling reaction. Their electrochemical polymerizations were carried out on ITO coated glass slides in a three electrode system. Electrochemical, spectral and kinetic results were given in detail and results showed that especially EDOT units in the conjugated system exert stronger influence on polymer electronic properties containing polymer hence it can be great candidate for electrochromic devices.
![Research paper thumbnail of Tailoring optoelectronic properties of thieno[3,2-b]thiophene comprising homopolymers via electron acceptor moieties: thienopyrrolodione, 2,1,3-benzoselenadiazole, isoindigo](https://attachments.academia-assets.com/107047252/thumbnails/1.jpg)
](Journal of Electroanalytical Chemistry, 2020
In this work, thieno[3,2-b]thiophene based homopolymers, namely poly(5,6-bis(octyloxy)-4,7-bis(th... more In this work, thieno[3,2-b]thiophene based homopolymers, namely poly(5,6-bis(octyloxy)-4,7-bis(thieno[3,2-b] thiophen-2-yl)benzo[c][1,2,5]selenadiazole; PBSeThTh), poly(5-(2-ethylhexyl)-1,3-bis(thieno[3,2-b]thiophen-2-yl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione; PTPDThTh) and poly((E)-6,6′-bis(thieno[3,2-b]thiophen-2-yl)-1,1′diundecyl-[3,3′-biindolinylidene]-2,2′-dione; PIIDThTh), were obtained potentiodynamically to tailor optoelectronic properties via altering electron acceptor moieties which were 5,6-bis(octyloxy)benzo[c][1,2,5]selenadiazole 5-(2ethylhexyl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (TPD) and (E)-1,1′-diundecyl-[3,3′-biindolinylidene]-2,2′-dione (IID). The polymers were characterized cyclic voltammetry and spectroelectrochemistry studies. All polymers reveal ambipolar and multichromic characteristics with broad spectral absorptions, low-lying highest occupied molecular orbital (−5.69 eV, −5.59 eV, −5.60 eV), and as well as low band gap ranging from 1.58 eV to 1.86 eV. Isoindigo comprising polymer resulted in the lowest optical band gap which was 1.16 eV due to a red shift in the absorption most probably due to richer electron density and strong inter-chain interactions, structural planarity.
Sensors and Actuators B: Chemical, 2016
Abstract In this study, a novel approach for the fabrication of a biosensor utilizing a conductin... more Abstract In this study, a novel approach for the fabrication of a biosensor utilizing a conducting polymer and silver nanowires is reported. To obtain immobilization platform for butyrylcholinesterase (BChE), a graphite electrode was modified with the poly(5,6-bis(octyloxy)-4,7-di(thieno[3][3,2-b]thiophen-2-yl)benzo[c][1,2,5]oxoadiazole) (PTTBO) which has a hydrophobic alkyl chain as the pendant group providing hydrophobic nature to the matrix. Since biomolecules contain both hydrophobic and hydrophilic parts in their structure, alkyl chains interact with the proteins which provide an enhanced stability. Biosensor performance was improved through the deposition of silver nanowires on the polymer coated surfaces which enhances the charge transfer rate. This enabled the development of rapid, highly sensitive and stable amperometric sensors for the quantitative determination of organophosphorus pesticide; paraoxon. Fabricated biosensor showed two linear ranges between 0.5–8 μM and 10–120 μM with a low detection limit of 0.212 μM when butyryl thiocholine iodide is used as the substrate. Surface modifications were monitored by scanning electron microscope (SEM) and cyclic voltammetry (CV) techniques. Under optimal operational parameters, fabricated sensors were tested for paraoxon detection in milk and tap water based on the inhibition of the enzyme molecules, where recovery tests proved the applicability of the designed system.
International Journal of Biological Macromolecules, 2019
A newly designed amperometric biosensor for the determination of ethanol through one-step electro... more A newly designed amperometric biosensor for the determination of ethanol through one-step electrochemical coating of (4,7-di(thiophen-2-yl)benzo[c][1,2,5]selenadiazole-co-1H-pyrrole-3-carboxylic acid) (TBeSe-co-P3CA) on a graphite electrode is presented. It was aimed to propose a newly synthesized copolymer with enhanced biosensing properties as a novel sensor for the quantification of ethanol. The conjugated copolymer (TBeSe-co-P3CA) was prepared through electrochemical polymerization by potential cycling. After polymer modification, alcohol oxidase (AOx) was immobilized on a modified electrode surface for ethanol sensing. In the analytical investigation, the calibration plot is linear above large concentration range (0.085 to 1.7 mM), where sensitivity is around 16.44 μA/mMcm 2 with a very low detection limit (LOD) of 0.052 mM based on the signal-to-noise ratio in short response time. Moreover, interfering effect of some possible compounds were examined and the capability of the biosensor in estimating ethanol content in commercial alcoholic beverages was also demonstrated. The results showed satisfactory accuracy of the developed sensor and confirm the proposed sensor has a potential for ethanol quantification compared to the currently used techniques.
Journal of Electroanalytical Chemistry, 2019
Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2... more Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2) were synthesized and characterized where 4,8-bis[5-(2-ethylhexyl) thiophen-2-yl] benzo[1,2-b:4,5-b'] dithiophene (BDT) was used as the donor unit. 2,3-Bis(3,4-bis(octyloxy)phenyl)-5,8-dibromoquinoxaline was used as the acceptor moiety and selenophene and furan were utilized as π bridges. Optoelectronic properties of the polymers were examined by electrochemical and spectroelectrochemical characterizations. In cyclic voltammetry (CV) studies, both polymers were found to be ambipolar. In anodic region, oxidation potentials were observed as 1.45 V and 1.15 V for P1 and P2 respectively, while reduction potentials were 0.65 V and 0.92 V. In cathodic region, redox potentials were found to be −1.36 V/−1.32 V and −2.0 V/−1.51 V for P1 and −1.45 V/−1.05 V and −2.15 V/−1.45 V for P2. Both polymers showed good solubility in common solvents. The synthesized polymers were used as photoactive layers in solar cell devices. P1-based device (ITO/PEDOT:PSS/P1:PC71BM (1:3, w/w)/LiF/Al) provided the best performance with a PCE of 4.04%, a VOC of 0.67 V, a JSC of 13.94 mA/cm2, and a FF of 43.3%.
New Journal of Chemistry
A sensing platform for catechol detection incorporating triple key materials based on SiNPs, D–A–... more A sensing platform for catechol detection incorporating triple key materials based on SiNPs, D–A–D type conducting polymer, and MWCNTs.
Journal of Electroanalytical Chemistry, 2021
Four novel alternating copolymers bearing 5-fluoro-6-((2-octyldodecyl)oxy)benzo[c][1,2,5]thiadiaz... more Four novel alternating copolymers bearing 5-fluoro-6-((2-octyldodecyl)oxy)benzo[c][1,2,5]thiadiazole as a strong acceptor unit and 9,9-dioctylfluorene as a strong donor unit with bridging units namely, thienothiophene, selenophene, 3-hexylthiophene, and thiophene were designed and synthesized. The polymers were characterized via 1 H NMR spectroscopy, and weight average molecular weights were reported via gel permeation chromatography (GPC). For synthesized novel polymers, the bulk heterojunction solar cells were constructed. Besides, the effects of bridging units on electronic, optical, photovoltaic, and morphological properties were investigated. Among the polymers, the thienothiophene containing polymer P1 exhibited the highest PCE as 4.25% under the illumination of AM 1.5 G with 100 mW/cm 2 .
Journal of The Electrochemical Society, 2021
Four novel benzo[c][1,2,5]thiadiazole comprising monomers namely 5-fluoro-6-((2-octyldodecyl)oxy)... more Four novel benzo[c][1,2,5]thiadiazole comprising monomers namely 5-fluoro-6-((2-octyldodecyl)oxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole (TBTT), 5-fluoro-4,7-bis(4-hexylthiophen-2-yl)-6-((2-octyldodecyl)oxy)benzo[c][1,2,5]thiadiazole (HTBTHT), 5-fluoro-4,7-di(furan-2-yl)-6-((2-octyldodecyl)oxy)benzo- [c][1,2,5]thiadiazole (FBTF), and 5-fluoro-6-((2-octyldodecyl)oxy)-4,7-bis(thieno[3,2-b]thiophen-2-yl)benzo[c][1,2,5]thiadiazole (TTBTTT) were designed, and synthesized successfully via Stille polycondensation reaction. The structural characterizations of the monomers were performed by 1H and 13C NMR spectroscopy and High Resolution Mass Spectroscopy (HRMS). The monomers were then electropolymerized in a three electrode cell system via cyclic voltammetry. The electrochemical, and spectroelectrochemical characterization of the polymers were reported in detail. Besides, theoretical calculations were performed to elucidate observed experimental properties. According to the cyclic ...
Journal of Polymer Science, 2020
Two novel conjugated near‐infrared (NIR) absorbing donor–acceptor type copolymers comprising benz... more Two novel conjugated near‐infrared (NIR) absorbing donor–acceptor type copolymers comprising benzodithiophene as the donor and [1,2,5]chalcogenazolo[3,4‐f]‐benzo[1,2,3]triazole derivatives as the acceptors, spaced with thiophene as the π‐bridge, were designed and synthesized via Stille polycondensation reaction. The effect of acceptor strength on optoelectronic properties was targeted and investigated. Branched alkyl chains (the extended 2‐octyl‐1‐dodecyl alkyl chain; C8C12) were introduced to 5H‐[1,2,3]triazolo[4′,5′:4,5]benzo[1,2‐c][1,2,5]thiadiazole and 5H‐[1,2,3]triazolo[4′,5′:4,5]benzo[1,2‐c][1,2,5]selenadiazole for enhanced solubility of polymers which ease the processability hence device constructions. The strongly electron‐withdrawing units lead to a substantial change in the absorption properties via promotion of the intramolecular charge transfer band alongside the π–π* transition. The resultant soluble polymers were characterized via cyclic voltammetry to determine highe...
Journal of Polymer Science Part A: Polymer Chemistry, 2019
ABSTRACTPresent work displays the preparation of an electrochemical biosensor using a conjugated ... more ABSTRACTPresent work displays the preparation of an electrochemical biosensor using a conjugated polymer and laccase enzyme for catechol quantification in samples. The biosensing system is based on an enzyme immobilization on polymer modified graphite transducer surface. For that purpose, a random conjugated polymer, thienothiophene‐benzoxadiazole‐alt‐benzodithiophene (BOTT), was coated onto a graphite electrode surface via drop casting method followed by immobilization of a biomolecule (laccase) for sensing experiments. Herein, for the first time, we proposed a BOTT polymer as an inexpensive and effective way to fabricate highly sensitive and fast response biosensors. The proposed sensing system possessed superior properties with 0.38 μM limit of detection and 110.81 μA mM−1 sensitivity. Furthermore, cyclic voltammetry and scanning electron microscopy techniques were used to examine the surface modifications. The proposed system could be useful for many future studies for catechol ...
New Journal of Chemistry, 2019
A novel sensing platform based on a newly designed and synthesized polymer, poly[(E)-6-methyl-6′-... more A novel sensing platform based on a newly designed and synthesized polymer, poly[(E)-6-methyl-6′-(10-methylanthracen-9-yl)-1,1′-diundecyl-[3,3′-biindolinylidene]-2,2′-dione] (namely PIIDAnth), was fabricated and explored as a glucose amperometric biosensor.
Journal of Electroanalytical Chemistry, 2019
Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2... more Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2) were synthesized and characterized where 4,8-bis[5-(2-ethylhexyl) thiophen-2-yl] benzo[1,2-b:4,5-b'] dithiophene (BDT) was used as the donor unit. 2,3-Bis(3,4-bis(octyloxy)phenyl)-5,8-dibromoquinoxaline was used as the acceptor moiety and selenophene and furan were utilized as π bridges. Optoelectronic properties of the polymers were examined by electrochemical and spectroelectrochemical characterizations. In cyclic voltammetry (CV) studies, both polymers were found to be ambipolar. In anodic region, oxidation potentials were observed as 1.45 V and 1.15 V for P1 and P2 respectively, while reduction potentials were 0.65 V and 0.92 V. In cathodic region, redox potentials were found to be −1.36 V/−1.32 V and −2.0 V/−1.51 V for P1 and −1.45 V/ −1.05 V and −2.15 V/−1.45 V for P2. Both polymers showed good solubility in common solvents. The synthesized polymers were used as photoactive layers in solar cell devices.
In this study, two donor-acceptor (D-A) type conjugated polymers namely PQSeCz and PQSeFl were de... more In this study, two donor-acceptor (D-A) type conjugated polymers namely PQSeCz and PQSeFl were designed and synthesized. Selenophene was incorporated as a π -bridge, quinoxaline as an acceptor unit while carbazole and fluorene were used as the donor units. Polymers were synthesized via palladium catalyzed Suzuki polymerization reaction. All molecules were characterized by 1H and 13C NMR Spectroscopy. The weight and number average molecular weights of the two polymers were determined by gel permeation chromatography (GPC). Electrochemical and spectroelectrochemical characterizations of the polymers were performed to investigate their optoelectronic properties. Oxidation potentials were 1.15 V/ 0.82 V and 1.11 V/ 0.82 V for PQSeCz and PQSeFl respectively, while reduction potentials were -1.26 V /-1.14 V and -1.48 V/ -1.23 V, respectively. In the visible region, maximum absorption wavelengths for the two polymers were 551 nm and 560 nm, respectively. Optical band gaps (Egop) were fo...
Journal of Electroanalytical Chemistry, 2017
Naphthodithiophene is a thiophene fused naphthalene with a rigid and planar structure with extend... more Naphthodithiophene is a thiophene fused naphthalene with a rigid and planar structure with extended π-conjugation system and due its electron rich nature it has been recently employed in donor-acceptor type conducting polymers. In this study, alkoxy functionalized naphthodithiophene bearing two new random copolymers namely poly4-(5″-(5,6-bis(dodecyloxy)naphtho[2,1-b:3,4-b′]dithiophen-2-yl)-[2,2′:5′,2″-terthiophen]-5-yl)-2-dodecyl-7-(thiophen-2-yl)-2H-benzo[d] [1,2,3]triazole (P1) and poly4-(5″″-(5,6-bis(dodecyloxy)naphtho[2,1-b:3,4-b′]dithiophen-2-yl)-[2,2′:5′,2″:5″,2″′:5″′,2″″-quinquethiophen]-5-yl)-2-dodecyl-7-(thiophen-2-yl)-2H-benzo[d] [1,2,3]triazole (P2) were synthesized via Stille coupling reaction in order to monitor the effect of thiophene and bithiophene bridge units on electrochemical and optical properties of the corresponding polymers. As the acceptor moiety in the polymer backbone electron deficient benzotriazole moiety was used. Thiophene and bithiophene units were used as π-linkers to enhance electron delocalization through polymer chain. Via alkoxy modification, synthesized polymers were highly soluble in common solvents like THF, chloroform, chlorobenzene. Altering π bridge from thiophene bridge to bithiophene, kinetic properties of the polymers were improved. Electrochemical studies revealed that while P1 has only p-dopable nature, P2 has ambipolar character. Change of π-bridge from thiophene to bithiophene has affected the optoelectronic properties of the polymers in a favorable manner for different application areas. The polymers exhibited low lying highest occupied molecular orbital (−5.40 eV for P1 and −5.30 eV for P2) and moderate band gaps which are 2.05 eV and 2.02 eV for P1 and P2, respectively.
Macromolecular Chemistry and Physics, 2017
Two low band gap triphenylamine based random copolymers are synthesized via Pd‐catalyzed Stille p... more Two low band gap triphenylamine based random copolymers are synthesized via Pd‐catalyzed Stille polycondensation reaction to investigate the role of molecular weight on device performance and optoelectronic properties. 1H NMR spectroscopy, UV−vis absorption spectroscopy, cyclic voltammetry, and gel permeation chromatography (GPC) are used for characterization of polymers. The polymerization conditions are optimized to achieve high molecular weight polymers with enhanced optoelectronic properties. PBTP1 reveals broad absorption in the wavelength range of 300–670 nm whereas PBTP2 has absorption in the wavelength range of 300–660 nm. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels are calculated as −5.43 and −3.20 eV for PBTP1 and −5.33 and −3.02 eV for PBTP2. The photovoltaic device containing donor PBTP1 and acceptor PCBM[70] in 1:3 weight ratio reveals the highest power conversion efficiency of 2.27%, with Voc of 0.63 V, Jsc of ...
New Journal of Chemistry, 2016
Influence of spacers on the optoelectronic properties of polymers.
Journal of Macromolecular Science, Part A, 2016
ABSTRACT Three novel donor-acceptor-donor type random copolymers based on benzothiadiazole (BTh) ... more ABSTRACT Three novel donor-acceptor-donor type random copolymers based on benzothiadiazole (BTh) and benzoselenadiazole (BSe) were synthesized via Pd (0) catalyzed Suzuki polycondensation reaction. The two acceptor units were coupled with electron rich moieties which are carbazole (CZ), fluorene (FL) and silafluorene (SiFL). Monomers were characterized using 1H and 13C-NMR spectroscopy. The number and weight average molecular weights of the polymers were calculated using gel permeation chromatography (GPC). All three polymers were electrochemically and spectroelectrochemically characterized. PBThBSeCZ, PBThBSeFL and PBThBSeSiFL showed only p-dopable character and their doping/dedoping potentials were determined as 1.4 V/1.2 V, 1.53 V/1.27 V and 1.8 V/1.3 V, respectively. Corresponding HOMO energy levels were calculated as −5.85 eV, −6.05 eV and −6.15 eV whereas LUMO energy levels were found to be −3.67 eV, −3.84 eV and −3.77 eV, respectively. PBThBSeCZ had lower HOMO level and band gap than PBThBSeFL and PBThBSeSiFL due to its increased electron donating capability of nitrogen atom in carbazole unit.
Journal of Polymer Science Part A: Polymer Chemistry, 2016
ABSTRACTFour new 2,1,3‐benzooxadiazole‐based donor–acceptor conjugated polymers, namely poly{9‐(9... more ABSTRACTFour new 2,1,3‐benzooxadiazole‐based donor–acceptor conjugated polymers, namely poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSC), poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFC), poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSFL), and poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFFL), were synthesized via Stille polycondensation reaction. All polymers were found to be soluble in common organic solvents such as chloroform, tetrahydrofuran, and chlorobenzene. Their structures were verified by 1H‐NMR and the molecular weights were determined by gel permeation chromatography (GPC). The polymer films exhibited broad absorption bands. Among all polymers, photovoltaic cells based on the device structure of ITO/PEDOT:PSS/PSBSC:PC71BM(1:3, w/...
Journal of Electroanalytical Chemistry, 2015
Synthetic Metals, 2014
Benzooxadiazole containing three monomers; 5,6-bis(octyloxy)-4,7-bis(4-hexylthiophen-2-yl)-2,1,3-... more Benzooxadiazole containing three monomers; 5,6-bis(octyloxy)-4,7-bis(4-hexylthiophen-2-yl)-2,1,3-benzoxadiazole (BOHT), 5,6-bis(octyloxy)-4,7-di-2-thienyl-2,1,3-benzoxadiazole (BODT) and 5,6-bis(octyloxy)-4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,1,3-benzoxadiazole (BODHT) were synthesized via Stille coupling reaction. Their electrochemical polymerizations were carried out on ITO coated glass slides in a three electrode system. Electrochemical, spectral and kinetic results were given in detail and results showed that especially EDOT units in the conjugated system exert stronger influence on polymer electronic properties containing polymer hence it can be great candidate for electrochromic devices.
Journal of Electroanalytical Chemistry, 2020
In this work, thieno[3,2-b]thiophene based homopolymers, namely poly(5,6-bis(octyloxy)-4,7-bis(th... more In this work, thieno[3,2-b]thiophene based homopolymers, namely poly(5,6-bis(octyloxy)-4,7-bis(thieno[3,2-b] thiophen-2-yl)benzo[c][1,2,5]selenadiazole; PBSeThTh), poly(5-(2-ethylhexyl)-1,3-bis(thieno[3,2-b]thiophen-2-yl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione; PTPDThTh) and poly((E)-6,6′-bis(thieno[3,2-b]thiophen-2-yl)-1,1′diundecyl-[3,3′-biindolinylidene]-2,2′-dione; PIIDThTh), were obtained potentiodynamically to tailor optoelectronic properties via altering electron acceptor moieties which were 5,6-bis(octyloxy)benzo[c][1,2,5]selenadiazole 5-(2ethylhexyl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (TPD) and (E)-1,1′-diundecyl-[3,3′-biindolinylidene]-2,2′-dione (IID). The polymers were characterized cyclic voltammetry and spectroelectrochemistry studies. All polymers reveal ambipolar and multichromic characteristics with broad spectral absorptions, low-lying highest occupied molecular orbital (−5.69 eV, −5.59 eV, −5.60 eV), and as well as low band gap ranging from 1.58 eV to 1.86 eV. Isoindigo comprising polymer resulted in the lowest optical band gap which was 1.16 eV due to a red shift in the absorption most probably due to richer electron density and strong inter-chain interactions, structural planarity.
Sensors and Actuators B: Chemical, 2016
Abstract In this study, a novel approach for the fabrication of a biosensor utilizing a conductin... more Abstract In this study, a novel approach for the fabrication of a biosensor utilizing a conducting polymer and silver nanowires is reported. To obtain immobilization platform for butyrylcholinesterase (BChE), a graphite electrode was modified with the poly(5,6-bis(octyloxy)-4,7-di(thieno[3][3,2-b]thiophen-2-yl)benzo[c][1,2,5]oxoadiazole) (PTTBO) which has a hydrophobic alkyl chain as the pendant group providing hydrophobic nature to the matrix. Since biomolecules contain both hydrophobic and hydrophilic parts in their structure, alkyl chains interact with the proteins which provide an enhanced stability. Biosensor performance was improved through the deposition of silver nanowires on the polymer coated surfaces which enhances the charge transfer rate. This enabled the development of rapid, highly sensitive and stable amperometric sensors for the quantitative determination of organophosphorus pesticide; paraoxon. Fabricated biosensor showed two linear ranges between 0.5–8 μM and 10–120 μM with a low detection limit of 0.212 μM when butyryl thiocholine iodide is used as the substrate. Surface modifications were monitored by scanning electron microscope (SEM) and cyclic voltammetry (CV) techniques. Under optimal operational parameters, fabricated sensors were tested for paraoxon detection in milk and tap water based on the inhibition of the enzyme molecules, where recovery tests proved the applicability of the designed system.
International Journal of Biological Macromolecules, 2019
A newly designed amperometric biosensor for the determination of ethanol through one-step electro... more A newly designed amperometric biosensor for the determination of ethanol through one-step electrochemical coating of (4,7-di(thiophen-2-yl)benzo[c][1,2,5]selenadiazole-co-1H-pyrrole-3-carboxylic acid) (TBeSe-co-P3CA) on a graphite electrode is presented. It was aimed to propose a newly synthesized copolymer with enhanced biosensing properties as a novel sensor for the quantification of ethanol. The conjugated copolymer (TBeSe-co-P3CA) was prepared through electrochemical polymerization by potential cycling. After polymer modification, alcohol oxidase (AOx) was immobilized on a modified electrode surface for ethanol sensing. In the analytical investigation, the calibration plot is linear above large concentration range (0.085 to 1.7 mM), where sensitivity is around 16.44 μA/mMcm 2 with a very low detection limit (LOD) of 0.052 mM based on the signal-to-noise ratio in short response time. Moreover, interfering effect of some possible compounds were examined and the capability of the biosensor in estimating ethanol content in commercial alcoholic beverages was also demonstrated. The results showed satisfactory accuracy of the developed sensor and confirm the proposed sensor has a potential for ethanol quantification compared to the currently used techniques.
Journal of Electroanalytical Chemistry, 2019
Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2... more Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2) were synthesized and characterized where 4,8-bis[5-(2-ethylhexyl) thiophen-2-yl] benzo[1,2-b:4,5-b'] dithiophene (BDT) was used as the donor unit. 2,3-Bis(3,4-bis(octyloxy)phenyl)-5,8-dibromoquinoxaline was used as the acceptor moiety and selenophene and furan were utilized as π bridges. Optoelectronic properties of the polymers were examined by electrochemical and spectroelectrochemical characterizations. In cyclic voltammetry (CV) studies, both polymers were found to be ambipolar. In anodic region, oxidation potentials were observed as 1.45 V and 1.15 V for P1 and P2 respectively, while reduction potentials were 0.65 V and 0.92 V. In cathodic region, redox potentials were found to be −1.36 V/−1.32 V and −2.0 V/−1.51 V for P1 and −1.45 V/−1.05 V and −2.15 V/−1.45 V for P2. Both polymers showed good solubility in common solvents. The synthesized polymers were used as photoactive layers in solar cell devices. P1-based device (ITO/PEDOT:PSS/P1:PC71BM (1:3, w/w)/LiF/Al) provided the best performance with a PCE of 4.04%, a VOC of 0.67 V, a JSC of 13.94 mA/cm2, and a FF of 43.3%.