Dr.Thanawee Chodjarusawad | Burapha University (original) (raw)

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Papers by Dr.Thanawee Chodjarusawad

Research paper thumbnail of Biosensors Based on Acetylcholinesterase Immobilized on Clay–Gold Nanocomposites for the Discrimination of Chlorpyrifos and Carbaryl

ACS omega, Oct 26, 2022

This work aims at evaluating a utilization of diverse clay mineral/gold nanoparticles/acetylcholi... more This work aims at evaluating a utilization of diverse clay mineral/gold nanoparticles/acetylcholinesterase (clay/ AuNPs/AChE) biosensors by using principal component analysis (PCA) for the discrimination of pesticide types and their concentration levels both in the synthetic and real samples. Applications of simple and low-cost clay/AuNP composites of different characteristics as modified-electrode materials are highlighted. Four types of clay minerals, namely, platelike kaolinite (Kaol: 1:1 aluminum phyllosilicate), globular montmorillonite (Mt: 2:1 aluminum phyllosilicate), globular bentonite (Bent: 2:1 aluminum phyllosilicate), and fibrous sepiolite (Sep: 2:1 inverted ribbons of magnesium phyllosilicate), were selected as the base materials. Due to the distinct characteristics of the selected clay, the derived clay/AuNP composites resulted in different physical morphologies, AuNP sizes and loadings, matrix hydrophobicity, and active AChE loading per electrode. These, in turn, caused divergent electrochemical responses for the pesticide determination; hence, no other enzymes apart from AChE were necessary for the fabrication of distinct biosensors. Physical and chemical characterizations of clay/AuNPs were conducted using scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy techniques. The electrochemical information was recorded by cyclic voltammetry and amperometry techniques. The enzyme inhibition results obtained from the pesticides were treated and used as input data to obtain PCA results. The four fabricated clay/AuNPs/AChE biosensors were able to discriminate chlorpyrifos and carbaryl and their concentration levels for synthetic pesticides and real samples. It was disclosed that a high enzyme inhibition and a high hydrophobic modified-electrode material affect a highly sensitive pesticide biosensor. The hydrophobic/hydrophilic character of the modified-electrode material plays a major role in discriminating the pesticide types and their concentration levels by the proposed single-enzyme sensor system. The PCA results illustrated that PC2 described the different types of pesticides, and PC1 showed the level of pesticide concentration with high first two principal components. The mixed pesticides could be identified at an especially low total concentration of 0.5 ng/mL in real samples.

Research paper thumbnail of Investigations of Talbot and Talbot–Lau effects with various light sources

Research paper thumbnail of Electrochemical sensor: preparation technique based on electronic tongue in fragrance

Materials Today: Proceedings

Abstract This research is aimed to investigate a sensing of fragrance using electronic tongue (E-... more Abstract This research is aimed to investigate a sensing of fragrance using electronic tongue (E-tongue) based on electrochemistry by various sample preparation techniques. The E-tongue has been designed and constructed based on the pattern classification. Various fragrances have been studied to evaluate the ability of E-tongue by cyclic voltammetry (CV) and data reduction techniques by principal component analysis (PCA). In this study, a vomeronasal organ is a proposed concept for detection the odor and a medium act as a solvent to entrap the odor particles. The result indicates that this technique is able to classify samples in terms of qualitative and quantitative analysis as well.

Research paper thumbnail of Poly(methyl methacrylate) and thiophene-coated single-walled carbon nanotubes for volatile organic compound discrimination

Japanese Journal of Applied Physics, Jan 26, 2016

Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were... more Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were fabricated for use in volatile organic compound (VOC) detection. Pristine SWNTs were separately coated with PMMA (PMMA/SWNTs) and thiophene (thiophene/SWNTs) by spin-coating. Pristine SWNTs showed the highest response to methanol, while PMMA/SWNTs enabled 5.4-fold improved dichloromethane detection and thiophene/SWNTs enabled 1.4-fold improved acetone detection compared with pristine SWNTs. The sensor response of PMMA/SWNTs to dichloromethane and that of thiophene/SWNTs to acetone can be attributed to the Hildebrand solubility parameter (HSP). The more similar the HSP, the higher the sensor response. The sensor response of pristine SWNTs to methanol is related to the diffusion coefficient and molecular size. The relationships between the vapor concentration and sensor response of PMMA/SWNTs to dichloromethane and thiophene/SWNTs to acetone are based on Henry's adsorption isotherm, w...

Research paper thumbnail of Impact of processing method and growing location on overall differences of brewed coffee using electronic tongue and sensory panel

Research paper thumbnail of Poly(methyl methacrylate) and thiophene-coated single-walled carbon nanotubes for volatile organic compound discrimination

Japanese Journal of Applied Physics, Jan 26, 2016

Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were... more Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were fabricated for use in volatile organic compound (VOC) detection. Pristine SWNTs were separately coated with PMMA (PMMA/SWNTs) and thiophene (thiophene/SWNTs) by spin-coating. Pristine SWNTs showed the highest response to methanol, while PMMA/SWNTs enabled 5.4-fold improved dichloromethane detection and thiophene/SWNTs enabled 1.4-fold improved acetone detection compared with pristine SWNTs. The sensor response of PMMA/SWNTs to dichloromethane and that of thiophene/SWNTs to acetone can be attributed to the Hildebrand solubility parameter (HSP). The more similar the HSP, the higher the sensor response. The sensor response of pristine SWNTs to methanol is related to the diffusion coefficient and molecular size. The relationships between the vapor concentration and sensor response of PMMA/SWNTs to dichloromethane and thiophene/SWNTs to acetone are based on Henry's adsorption isotherm, while that of pristine SWNTs to methanol is based on the Henry–clustering model. Principal component analysis (PCA) results show that dichloromethane, acetone, and methanol were successfully discriminated.

Research paper thumbnail of Study of Acid-Treated Multiwall Carbon Nanotubes by Electron Microscopy and Raman Spectroscopy

Research paper thumbnail of Electrochemical sensor: preparation technique based on electronic tongue in fragrance

Materials Today: Proceedings, 2017

Abstract This research is aimed to investigate a sensing of fragrance using electronic tongue (E-... more Abstract This research is aimed to investigate a sensing of fragrance using electronic tongue (E-tongue) based on electrochemistry by various sample preparation techniques. The E-tongue has been designed and constructed based on the pattern classification. Various fragrances have been studied to evaluate the ability of E-tongue by cyclic voltammetry (CV) and data reduction techniques by principal component analysis (PCA). In this study, a vomeronasal organ is a proposed concept for detection the odor and a medium act as a solvent to entrap the odor particles. The result indicates that this technique is able to classify samples in terms of qualitative and quantitative analysis as well.

Research paper thumbnail of Synthesis and Characterization of Zinc Oxide-Reduced Graphene Oxide Hybrid Materials and their Application for Nitrogen Dioxide Detection

Solid State Phenomena, 2020

Herein, we report a facile synthesis of zinc oxide-reduced graphene oxide (ZnO-rGO) hybrid materi... more Herein, we report a facile synthesis of zinc oxide-reduced graphene oxide (ZnO-rGO) hybrid materials by two-step method. Firstly, rGO was synthesized by using graphite powder mixed with sodium nitrate, sulfuric acid and potassium permanganate via Hummers method. Synthesized rGO were dispersed in ethanol by ultra-sonication for a designated time period. Then, zinc oxide (ZnO) powder was added into rGO-ethanol solution and transferred into Teflon-lined stainless steel autoclave. The ZnO-rGO was produced by hydrothermal method at 180 °C for 120 and 180 min (here after referred to as ZnO(120)-rGO and ZnO(180)-rGO, respectively). The morphological and crystalline structures of synthesized rGO and ZnO-rGO were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Synthesized ZnO-rGO was exposed to 100 parts per million (ppm) nitrogen dioxide (NO2) gas at room temperature, 50 °C and 75 °C for testing its sensing performanc...

Research paper thumbnail of Effective hydrogen gas sensor based on palladium nanoparticles dispersed on graphene sheets by spin coating technique

Materials Science-Poland, 2020

A room-temperature hydrogen gas (H2) sensor was successfully fabricated by dispersion of palladiu... more A room-temperature hydrogen gas (H2) sensor was successfully fabricated by dispersion of palladium nanoparticles (Pd NPs) on graphene sheets (GRs) (hereafter referred to as “Pd NPs/GRs”). GRs and Pd NPs were synthesized by chemical vapor deposition technique and by polyol process, respectively. A colloidal solution of Pd NPs with an average diameter of 11 nm was then dispersed onto the GRs by spin coating technique. The density of dispersed Pd NPs on GRs was controlled by varying the volume of the dispersed solution within the range of 50 – 150 μL. The fabricated Pd NPs/GRs sensors exhibited a high sensitivity for H2 gas with a concentration of 1500 – 6000 ppm at room temperature. Upon H2 exposure, the Pd NPs/GRs sensors showed an increase in electrical resistance, which could easily be measured. The relationship between sensor response and H2 concentration is in correspondence with the Langmuir adsorption model. The H2 detection limit is estimated to be 1 ppm. The results demonstra...

Research paper thumbnail of The study of UV protection materials

Most people are aware of how harmful UV radiation is to the skin. The sun’s ultraviolet rays, UVA... more Most people are aware of how harmful UV radiation is to the skin. The sun’s ultraviolet rays, UVA and UVB, are known to cause skin damage, from freckling and moles to fatal skin cancer. That’s why it is important to apply sunscreen products to your skin, to help you stay sun safe and absorber harmful ultraviolet rays. This research is studied to focus on how to make UV materials to protect UV radiation. The UV absorber additive materials are 4 types; nanoZnO solid powder at size 25-50 nm (ZnO-1), nanoZnO 40%wt in ethanol solution (ZnO-2), nano TiO2 solid powder at size 17-50 nm (TiO2-1) and nano TiO2 solid powder 325 mesh (TiO2-2) respectively, that was mixed in pure baby lotion cream. Three concentration of UV absorber additive materials are 5, 10 and 15 % by weight were compared with pure baby lotion cream. All compositions were tested UV absorbance with UV spectroscopy together with studied micro structure of UV absorber additive materials by Field emission scanning electron micr...

Research paper thumbnail of Impact of processing method and growing location on overall differences of brewed coffee using electronic tongue and sensory panel

Research paper thumbnail of A Study of Fluorescent Chemosensor for Fe(II) Based On Cyanoacrylic Derivatives

A chemosensor based on a cyanoacrylic (DTP-C) consists of dithieno[3,2-b;2’,3’-d]pyrrole(DTP) as ... more A chemosensor based on a cyanoacrylic (DTP-C) consists of dithieno[3,2-b;2’,3’-d]pyrrole(DTP) as a chromophore and a cyanoacrylic moiety as an ionophore which linked by aromatic system. DTP-C demonstrates the response of complex with Fe(II) in dimethylformamide (DMF) solution. The binding mode of Fe(II)/DTP-C complex was characterized using UV-Visible and fluorescence spectroscopy. In addition, the effect of various MES buffer was then studied at 5%, 10%, 15% and 20% v/v in Fe(II)/DTP-C complex which the appropriate ratiomatric of MES buffer is 10%. The enhancement of Fe(II) concentration indicate a decrease emission intensity while the addition of buffer concentrations found to increase in the intensity. Moreover, quantum chemical calculations were used to study the electronic and optical properties of the molecular structure of DTP-C under the density functional theory.

Research paper thumbnail of Ultraviolet Sensor Based on Organic/Inorganic Heterojunction between PEDOT:PSS and ZnO Nanoparticles Thin Films

Advanced Materials Research, 2015

In this work, the ultraviolet (UV) sensors based on heterojunction between layer of zinc oxide na... more In this work, the ultraviolet (UV) sensors based on heterojunction between layer of zinc oxide nanoparticles (ZnO NPs) and poly (3,4-ethylenedioxythiophene):poly (styrenesulfonic acid) (PEDOT:PSS) were fabricated, characterized and studied in the electrical response to UV 365 nm. The ZnO NPs layer was solution-based coated on the top of PEDOT:PSS film on the patterned indium tin oxide (ITO) coated on glass. Aluminum was deposited as the top electrode of the device. The current-voltage (I-V) characteristic shows the rectifying behavior in the dark field. With the UV irradiation, the reverse bias current can be found and the forward bias current also highly increases. The current-voltage data fitting with the thermionic emission model shows that the potential barrier height at the heterojunction decreases with illuminating by UV light. Relative high photoresponse of the device exhibits the potential to UV detector application.

Research paper thumbnail of Relationship between overall difference decision and electronic tongue: Discrimination of civet coffee

Journal of Food Engineering, 2016

Research paper thumbnail of Poly(methyl methacrylate) and thiophene-coated single-walled carbon nanotubes for volatile organic compound discrimination

Japanese Journal of Applied Physics, 2016

Research paper thumbnail of Classification of Fertilizer Solutions by Micro-Volume Voltammetric Electronic Tongue with Two Sensing Electrodes

Advanced Materials Research, 2015

A micro-volume electronic tongue based on cyclic voltammetry with two sensing electrodes (gold an... more A micro-volume electronic tongue based on cyclic voltammetry with two sensing electrodes (gold and carbon) and a platinum pseudo-reference electrode is proposed to classify fertilizers and monitor fertilizer uptakes. The electronic tongue has been employed to classify three different types of commercial fertilizers and their mixture. The nutrient uptake of Dracaena Sanderiana (D. Sanderiana) planted in crystal soil with the mixture fertilizer was monitored by sampling the fertilizer solutions with the electronic tongue over a period of one week. The contents of macronutrients in the solutions were also analyzed by the standard spectroscopic techniques for comparison. A good agreement is obtained between the relative uptakes of phosphate and potassium from the electronic tongue analysis and those from the standard analytical techniques.

Research paper thumbnail of Biosensors Based on Acetylcholinesterase Immobilized on Clay–Gold Nanocomposites for the Discrimination of Chlorpyrifos and Carbaryl

ACS omega, Oct 26, 2022

This work aims at evaluating a utilization of diverse clay mineral/gold nanoparticles/acetylcholi... more This work aims at evaluating a utilization of diverse clay mineral/gold nanoparticles/acetylcholinesterase (clay/ AuNPs/AChE) biosensors by using principal component analysis (PCA) for the discrimination of pesticide types and their concentration levels both in the synthetic and real samples. Applications of simple and low-cost clay/AuNP composites of different characteristics as modified-electrode materials are highlighted. Four types of clay minerals, namely, platelike kaolinite (Kaol: 1:1 aluminum phyllosilicate), globular montmorillonite (Mt: 2:1 aluminum phyllosilicate), globular bentonite (Bent: 2:1 aluminum phyllosilicate), and fibrous sepiolite (Sep: 2:1 inverted ribbons of magnesium phyllosilicate), were selected as the base materials. Due to the distinct characteristics of the selected clay, the derived clay/AuNP composites resulted in different physical morphologies, AuNP sizes and loadings, matrix hydrophobicity, and active AChE loading per electrode. These, in turn, caused divergent electrochemical responses for the pesticide determination; hence, no other enzymes apart from AChE were necessary for the fabrication of distinct biosensors. Physical and chemical characterizations of clay/AuNPs were conducted using scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy techniques. The electrochemical information was recorded by cyclic voltammetry and amperometry techniques. The enzyme inhibition results obtained from the pesticides were treated and used as input data to obtain PCA results. The four fabricated clay/AuNPs/AChE biosensors were able to discriminate chlorpyrifos and carbaryl and their concentration levels for synthetic pesticides and real samples. It was disclosed that a high enzyme inhibition and a high hydrophobic modified-electrode material affect a highly sensitive pesticide biosensor. The hydrophobic/hydrophilic character of the modified-electrode material plays a major role in discriminating the pesticide types and their concentration levels by the proposed single-enzyme sensor system. The PCA results illustrated that PC2 described the different types of pesticides, and PC1 showed the level of pesticide concentration with high first two principal components. The mixed pesticides could be identified at an especially low total concentration of 0.5 ng/mL in real samples.

Research paper thumbnail of Investigations of Talbot and Talbot–Lau effects with various light sources

Research paper thumbnail of Electrochemical sensor: preparation technique based on electronic tongue in fragrance

Materials Today: Proceedings

Abstract This research is aimed to investigate a sensing of fragrance using electronic tongue (E-... more Abstract This research is aimed to investigate a sensing of fragrance using electronic tongue (E-tongue) based on electrochemistry by various sample preparation techniques. The E-tongue has been designed and constructed based on the pattern classification. Various fragrances have been studied to evaluate the ability of E-tongue by cyclic voltammetry (CV) and data reduction techniques by principal component analysis (PCA). In this study, a vomeronasal organ is a proposed concept for detection the odor and a medium act as a solvent to entrap the odor particles. The result indicates that this technique is able to classify samples in terms of qualitative and quantitative analysis as well.

Research paper thumbnail of Poly(methyl methacrylate) and thiophene-coated single-walled carbon nanotubes for volatile organic compound discrimination

Japanese Journal of Applied Physics, Jan 26, 2016

Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were... more Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were fabricated for use in volatile organic compound (VOC) detection. Pristine SWNTs were separately coated with PMMA (PMMA/SWNTs) and thiophene (thiophene/SWNTs) by spin-coating. Pristine SWNTs showed the highest response to methanol, while PMMA/SWNTs enabled 5.4-fold improved dichloromethane detection and thiophene/SWNTs enabled 1.4-fold improved acetone detection compared with pristine SWNTs. The sensor response of PMMA/SWNTs to dichloromethane and that of thiophene/SWNTs to acetone can be attributed to the Hildebrand solubility parameter (HSP). The more similar the HSP, the higher the sensor response. The sensor response of pristine SWNTs to methanol is related to the diffusion coefficient and molecular size. The relationships between the vapor concentration and sensor response of PMMA/SWNTs to dichloromethane and thiophene/SWNTs to acetone are based on Henry's adsorption isotherm, w...

Research paper thumbnail of Impact of processing method and growing location on overall differences of brewed coffee using electronic tongue and sensory panel

Research paper thumbnail of Poly(methyl methacrylate) and thiophene-coated single-walled carbon nanotubes for volatile organic compound discrimination

Japanese Journal of Applied Physics, Jan 26, 2016

Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were... more Poly(methyl methacrylate) (PMMA) and thiophene-coated single-walled carbon nanotubes (SWNTs) were fabricated for use in volatile organic compound (VOC) detection. Pristine SWNTs were separately coated with PMMA (PMMA/SWNTs) and thiophene (thiophene/SWNTs) by spin-coating. Pristine SWNTs showed the highest response to methanol, while PMMA/SWNTs enabled 5.4-fold improved dichloromethane detection and thiophene/SWNTs enabled 1.4-fold improved acetone detection compared with pristine SWNTs. The sensor response of PMMA/SWNTs to dichloromethane and that of thiophene/SWNTs to acetone can be attributed to the Hildebrand solubility parameter (HSP). The more similar the HSP, the higher the sensor response. The sensor response of pristine SWNTs to methanol is related to the diffusion coefficient and molecular size. The relationships between the vapor concentration and sensor response of PMMA/SWNTs to dichloromethane and thiophene/SWNTs to acetone are based on Henry's adsorption isotherm, while that of pristine SWNTs to methanol is based on the Henry–clustering model. Principal component analysis (PCA) results show that dichloromethane, acetone, and methanol were successfully discriminated.

Research paper thumbnail of Study of Acid-Treated Multiwall Carbon Nanotubes by Electron Microscopy and Raman Spectroscopy

Research paper thumbnail of Electrochemical sensor: preparation technique based on electronic tongue in fragrance

Materials Today: Proceedings, 2017

Abstract This research is aimed to investigate a sensing of fragrance using electronic tongue (E-... more Abstract This research is aimed to investigate a sensing of fragrance using electronic tongue (E-tongue) based on electrochemistry by various sample preparation techniques. The E-tongue has been designed and constructed based on the pattern classification. Various fragrances have been studied to evaluate the ability of E-tongue by cyclic voltammetry (CV) and data reduction techniques by principal component analysis (PCA). In this study, a vomeronasal organ is a proposed concept for detection the odor and a medium act as a solvent to entrap the odor particles. The result indicates that this technique is able to classify samples in terms of qualitative and quantitative analysis as well.

Research paper thumbnail of Synthesis and Characterization of Zinc Oxide-Reduced Graphene Oxide Hybrid Materials and their Application for Nitrogen Dioxide Detection

Solid State Phenomena, 2020

Herein, we report a facile synthesis of zinc oxide-reduced graphene oxide (ZnO-rGO) hybrid materi... more Herein, we report a facile synthesis of zinc oxide-reduced graphene oxide (ZnO-rGO) hybrid materials by two-step method. Firstly, rGO was synthesized by using graphite powder mixed with sodium nitrate, sulfuric acid and potassium permanganate via Hummers method. Synthesized rGO were dispersed in ethanol by ultra-sonication for a designated time period. Then, zinc oxide (ZnO) powder was added into rGO-ethanol solution and transferred into Teflon-lined stainless steel autoclave. The ZnO-rGO was produced by hydrothermal method at 180 °C for 120 and 180 min (here after referred to as ZnO(120)-rGO and ZnO(180)-rGO, respectively). The morphological and crystalline structures of synthesized rGO and ZnO-rGO were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Synthesized ZnO-rGO was exposed to 100 parts per million (ppm) nitrogen dioxide (NO2) gas at room temperature, 50 °C and 75 °C for testing its sensing performanc...

Research paper thumbnail of Effective hydrogen gas sensor based on palladium nanoparticles dispersed on graphene sheets by spin coating technique

Materials Science-Poland, 2020

A room-temperature hydrogen gas (H2) sensor was successfully fabricated by dispersion of palladiu... more A room-temperature hydrogen gas (H2) sensor was successfully fabricated by dispersion of palladium nanoparticles (Pd NPs) on graphene sheets (GRs) (hereafter referred to as “Pd NPs/GRs”). GRs and Pd NPs were synthesized by chemical vapor deposition technique and by polyol process, respectively. A colloidal solution of Pd NPs with an average diameter of 11 nm was then dispersed onto the GRs by spin coating technique. The density of dispersed Pd NPs on GRs was controlled by varying the volume of the dispersed solution within the range of 50 – 150 μL. The fabricated Pd NPs/GRs sensors exhibited a high sensitivity for H2 gas with a concentration of 1500 – 6000 ppm at room temperature. Upon H2 exposure, the Pd NPs/GRs sensors showed an increase in electrical resistance, which could easily be measured. The relationship between sensor response and H2 concentration is in correspondence with the Langmuir adsorption model. The H2 detection limit is estimated to be 1 ppm. The results demonstra...

Research paper thumbnail of The study of UV protection materials

Most people are aware of how harmful UV radiation is to the skin. The sun’s ultraviolet rays, UVA... more Most people are aware of how harmful UV radiation is to the skin. The sun’s ultraviolet rays, UVA and UVB, are known to cause skin damage, from freckling and moles to fatal skin cancer. That’s why it is important to apply sunscreen products to your skin, to help you stay sun safe and absorber harmful ultraviolet rays. This research is studied to focus on how to make UV materials to protect UV radiation. The UV absorber additive materials are 4 types; nanoZnO solid powder at size 25-50 nm (ZnO-1), nanoZnO 40%wt in ethanol solution (ZnO-2), nano TiO2 solid powder at size 17-50 nm (TiO2-1) and nano TiO2 solid powder 325 mesh (TiO2-2) respectively, that was mixed in pure baby lotion cream. Three concentration of UV absorber additive materials are 5, 10 and 15 % by weight were compared with pure baby lotion cream. All compositions were tested UV absorbance with UV spectroscopy together with studied micro structure of UV absorber additive materials by Field emission scanning electron micr...

Research paper thumbnail of Impact of processing method and growing location on overall differences of brewed coffee using electronic tongue and sensory panel

Research paper thumbnail of A Study of Fluorescent Chemosensor for Fe(II) Based On Cyanoacrylic Derivatives

A chemosensor based on a cyanoacrylic (DTP-C) consists of dithieno[3,2-b;2’,3’-d]pyrrole(DTP) as ... more A chemosensor based on a cyanoacrylic (DTP-C) consists of dithieno[3,2-b;2’,3’-d]pyrrole(DTP) as a chromophore and a cyanoacrylic moiety as an ionophore which linked by aromatic system. DTP-C demonstrates the response of complex with Fe(II) in dimethylformamide (DMF) solution. The binding mode of Fe(II)/DTP-C complex was characterized using UV-Visible and fluorescence spectroscopy. In addition, the effect of various MES buffer was then studied at 5%, 10%, 15% and 20% v/v in Fe(II)/DTP-C complex which the appropriate ratiomatric of MES buffer is 10%. The enhancement of Fe(II) concentration indicate a decrease emission intensity while the addition of buffer concentrations found to increase in the intensity. Moreover, quantum chemical calculations were used to study the electronic and optical properties of the molecular structure of DTP-C under the density functional theory.

Research paper thumbnail of Ultraviolet Sensor Based on Organic/Inorganic Heterojunction between PEDOT:PSS and ZnO Nanoparticles Thin Films

Advanced Materials Research, 2015

In this work, the ultraviolet (UV) sensors based on heterojunction between layer of zinc oxide na... more In this work, the ultraviolet (UV) sensors based on heterojunction between layer of zinc oxide nanoparticles (ZnO NPs) and poly (3,4-ethylenedioxythiophene):poly (styrenesulfonic acid) (PEDOT:PSS) were fabricated, characterized and studied in the electrical response to UV 365 nm. The ZnO NPs layer was solution-based coated on the top of PEDOT:PSS film on the patterned indium tin oxide (ITO) coated on glass. Aluminum was deposited as the top electrode of the device. The current-voltage (I-V) characteristic shows the rectifying behavior in the dark field. With the UV irradiation, the reverse bias current can be found and the forward bias current also highly increases. The current-voltage data fitting with the thermionic emission model shows that the potential barrier height at the heterojunction decreases with illuminating by UV light. Relative high photoresponse of the device exhibits the potential to UV detector application.

Research paper thumbnail of Relationship between overall difference decision and electronic tongue: Discrimination of civet coffee

Journal of Food Engineering, 2016

Research paper thumbnail of Poly(methyl methacrylate) and thiophene-coated single-walled carbon nanotubes for volatile organic compound discrimination

Japanese Journal of Applied Physics, 2016

Research paper thumbnail of Classification of Fertilizer Solutions by Micro-Volume Voltammetric Electronic Tongue with Two Sensing Electrodes

Advanced Materials Research, 2015

A micro-volume electronic tongue based on cyclic voltammetry with two sensing electrodes (gold an... more A micro-volume electronic tongue based on cyclic voltammetry with two sensing electrodes (gold and carbon) and a platinum pseudo-reference electrode is proposed to classify fertilizers and monitor fertilizer uptakes. The electronic tongue has been employed to classify three different types of commercial fertilizers and their mixture. The nutrient uptake of Dracaena Sanderiana (D. Sanderiana) planted in crystal soil with the mixture fertilizer was monitored by sampling the fertilizer solutions with the electronic tongue over a period of one week. The contents of macronutrients in the solutions were also analyzed by the standard spectroscopic techniques for comparison. A good agreement is obtained between the relative uptakes of phosphate and potassium from the electronic tongue analysis and those from the standard analytical techniques.