Responsive Supramolecular Polythiophene Assemblies (original) (raw)
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Polythiophene-Based Chemical Sensors: Toward On-Site Supramolecular Analytical Devices
Bulletin of the Chemical Society of Japan
Polythiophene (PT) derivatives are in the spotlight as functional materials with their conductivity and optical properties, which depend on the distortion of coplanarity of the flexible backbone. The PT derivatives can be applied to chemical sensors owing to their tunable chemical and physical properties, while on-site sensing in aqueous media using PT-based solidstate devices is still challenging. In this Account, we describe a strategy for on-site supramolecular analytical devices. To maximize the applicability of PTs, we designed two types of PTbased chemical sensors. In the optical sensors, microarrays made of a hydrogel containing PTs on portable glass chips can simultaneously analyze multi-analytes combined with pattern recognition techniques. The various optical responses by adding analytes on the microarray chips can be recorded by easy-tohandle methods such as a digital camera, achieving on-site and high-throughput analysis without large spectrophotometers. Next, water-gated polythiophene transistors can offer highly sensitive detection due to a synergy effect of field-effect doping and interfacial charge modulation. Moreover, the electrical device with a microfluidic chamber allows real-time monitoring. We believe that our approaches would be a guideline to pave the way for the realization of supramolecular analytical devices.
Polythiophene based fluorescence sensors for acids and metal ions
Sensors and Actuators B: Chemical, 2009
Poly(thiophene-3-yl-acetic acid 8-quinolinyl ester) is a fluorescent material and it shows fluorescence at 540 nm. The fluorescence of poly (thiophene-3-yl-acetic acid 8-quinolinyl ester) has been studied in the presence of acids, metal ions, nucleotides and protein (l-proline). The fluorescence of polymer is quenched by the addition of HCl which could be recovered by the addition of equivalent amount of alkali. The Stern-Volmer quenching coefficient for HCl is calculated and found to be 141 M −1 . Moreover quenching depends on concentration of HCl. Similarly, the fluorescence of polymer is quenched by copper, cadmium and lead metal ions and quenching is sensitive to concentrations of metal ions. The Stern-Volmer quenching coefficient is 2.285 × 10 3 M −1 for Cu 2+ ions, 2.287 × 10 3 M −1 for Cd 2+ ions and 3.7 × 10 4 M −1 for Pb 2+ ions. In Al 3+ , Zn 2+ , nucleotides and protein (l-proline), the fluorescence is exorbitantly increased.
Tetrahedron, 2004
Regioregular polythiophenes with pendant carboxylic acid functionality, poly(thiophene-3-propionic acid) (PTPA, 3) and poly(thiophene-3-octanoic acid) (PTOA, 4), were prepared as water soluble conducting polymers and their chemosensory response was studied. Treatment with aqueous base generated intensely colored water soluble conducting polymer salts, with the color varying both as a function of counter ion size and length of the carboxyalkyl substituent. PTPA showed a different colorimetric response to each of the alkali earth metals whereas the longer chain PTOA was only sensitive to ions larger than Et 4 N C . Distinct color changes were also noted in studies of divalent cations known to selectively bind carboxylates, such as Zn 2C , Mn 2C , and Cd 2C . Cast films of PTPA have been found to act as sensors to acid vapor (Dl max of up to 132 nm). IR shows that the polymer self-assembles upon HCl vapor exposure, and that the process is completely reversible, leading to a good solid-state sensor for acids. This work demonstrates that regioregular polythiophenes containing acid side-chains have tremendous potential in the development of new sensors. q
A new polythiophene derivative with highly sensitive and selective affinitychromism properties
Synthetic Metals, 2007
A new poly(3-alkyl)thiophene bearing a piperidinic moiety in the side chain was synthesized in different ways with satisfactory yields in soluble fractions at high molecular weights. The chromic behaviors of the different polymeric samples were studied by UV-vis spectroscopy in different solvent/non-solvent mixtures and in the presence of some analytes; a strong affinitychromism toward bicarboxylic acids was observed. The good chromic response and its independence from the structural parameters of the polymer indicate the development of a very useful and easily obtainable colorimetric tool for the quick, sensitive and selective detection of diacid molecules in organic solvents.
Multicolor, large-area fluorescence sensing through oligothiophene-self-assembled monolayers
Chemical Communications, 2011
We present a new strategy to realize self-assembled monolayers (SAMs) on quartz and silicon with a multicolour fluorescence pattern starting from a single, proton sensitive oligothiophene dye exposed at a defined pH. Fine tuning of the SAMs emission color over the entire visible range, including white, is demonstrated. Finally, integration of SAMs in patterned thin layer cells (TLCs) is exploited to demonstrate cation sensing potential in real devices.
Synthetic Metals, 2015
Conjugated polyelectrolyte with polythiophene main chain and imidazolium side groups, poly{3-[6-(1methylimidazolium-3-yl) hexyl]thiophene-2,5-diyl bromide}, is investigated. Polymer architecture with hydrophobic main chain and hydrophilic side groups is responsible for the inconvenient behavior of the polymer in solution. Absorption and emission characteristics and supramolecular assembling are investigated by spectroscopic, microscopic and light-scattering methods. We report significant solvatochromism which is observable by a naked eye. Water solutions and mixed solvent systems exhibit most interesting features: supramolecular assembling was investigated by DLS, AFM and TEM techniques and common spectroscopic methods such as UV-vis and fluorescence spectroscopy. Moreover, slow relaxation processes take part in water as it is evidenced by time evolution of absorption spectra. It is a result of vanishing of inter-and intramolecular interactions. These interactions are responsible for extraordinary solution behavior of the ionic polythiophene.
In the present work, we performed a comparative investigation of spectroelectrochemical and biosensor application of isomeric thienylpyrrole derivatives. For this purpose two thienylpyrrole derivatives were synthesized characterized and electrochemically polymerized. Characterizations of the resulting polymers were performed by cyclic voltammetry (CV), UV-vis spectroscopy. Moreover, the spectroelectrochemical, electrochromic properties and biosensing applications of the polymer films were investigated. The resulting polymer films have distinct electrochromic properties and show five different colors. The 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)aniline (SNS-NH2) and 3-(2,5-di(thiophen- 2-yl)-1H-pyrrol-1-yl)aniline P(SNS-mNH2) films show maximum optical contrast (DT%) of 41.5%, 25.4% at 431 nm, 422 nm with a response time of 1.5 s. For biosensing studies, P(SNS-NH2) and P(SNS-mNH2) were polymerized on graphite electrodes electrochemically and used as immobilization matrices. After electrochemical deposition, glucose oxidase (GOx) was immobilized on the modified electrodes as the model enzyme. Effects of the position of the amine group on spectroelectrochemical properties and biosensing capability of the polymers were investigated.
We report a multi-stimuli responsive polymeric sensor consisting of a pseudorotaxane-like architecture fabricated from a 1,5-diaminonaphthalene end-functionalized poly(N-isopropyl)acrylamide (Napht-N-PNIPAM) and cyclobis(paraquat-p-phenylene) (CBPQT 4+ , 4Cl À ). The coloured nature of the poly-pseudorotaxane provides a sensor for temperature and pH in water with an associated visible readout. To create this dual responsive polymeric sensor, a new chain transfer agent (Napht-N-CTA) incorporating a pH-responsive 1,5-diaminonaphthalene unit was synthesized and used for the polymerization of N-isopropylacrylamide via Reversible Addition-Fragmentation Chain Transfer (RAFT). The ability of Napht-N-PNIPAM to form a pseudorotaxane architecture with CBPQT 4+ , 4Cl À in aqueous media was studied by means of UV-Vis, NMR ( 1 H, 2D-ROESY, DOSY) and ITC experiments. Interestingly, the pseudorotaxane architecture can be reversibly dissociated upon either heating the sample above its cloud point or protonating the nitrogen atoms of the 1,5-diaminonaphthalene-based guest unit by adjusting the pH to around 1. In both cases a dramatic colour change occurs from intense blue-green to colourless.