Electropolymerized Molecularly Imprinted Polypyrrole Film for Sensing of Clofibric Acid

Abstract

Piezoelectric quartz crystals and analogous gold substrates were electrochemically coated with molecularly imprinted polypyrrole films for pulsed amperometric detection (PAD) of clofibric acid, a metabolite of clofibrate. Cyclic voltammetry data obtained during polymerization and deposited weight estimations revealed a decrease of the polymerization rate with increasing clofibric acid concentration. XPS measurements indicated that clofibric acid could be removed after imprinting with an aqueous ethanol solution, which was further optimized by using PAD. Zeta potential and contact angle measurements revealed differences between molecularly imprinted (MIP) and non-imprinted polymer (NIP) layers. Binding experiments with clofibric acid and other substances showed a pronounced selectivity of the MIP for clofibric acid vs. carbamazepine, but the response of MIP and NIP to 2,4-dichlorophenoxyacetic acid was higher than that for clofibric acid. A smooth surface, revealed by AFM measurements, with roughness of 6–8 nm for imprinted and non-imprinted layers, might be a reason for an excessively low density of specific binding sites for clofibric acid. Furthermore, the decreased polymerization rate in the presence of clofibric acid might not result in well-defined polymer structures, which could be the reason for the lower sensitivity.

Over‐Oxidized Poly (Phenol Red) Film Modified Glassy Carbon Electrode for Anodic Stripping Voltammetric Determination of Ultra‐Trace Antimony (III)

“…The curve fitting of the C1 s peaks for PPhRed and PPhRed ox has been done by assuming three components at 284.7, 286.2, 289.9 eV and 285.4, 287.2, 289.037, respectively (Figure A). These values could correspond to sp 2 carbon in the polymer chain, C=O bond, and HO–C=O/O‐C=O − bond, respectively . As expected, C1s after over‐oxidation of PPhRed (Figure B) shows an increase of component at 289.9 attributed to COOH/COO − functionalities, in comparison to C1s in PPhRed (Figure A).…”

“…Three oxygen species were observed with the PPhRed/GCE (Figure B‐1) at BE 531.7, 533.3 and 536.1 eV. The lower BE signal (531.7 eV) could be assigned to ‐C=O bond . The BE at 533.7 eV could be owing to C−O‐C in the polymeric structure and the BE at 536.1 eV could be relevant to adsorbed water and this peak is also characteristic of ‐C=O bond in which compounds containing the functional group ‐O‐C=O .…”

Selectivity and Efficiency of Conductive Molecularly Imprinted Polymer (c-MIP) Based on 5-Phenyl-Dipyrromethane and 5-Phenol-Dipyrromethane for Quorum Sensing Precursors Detection

“…The formed film was about 100-130 nm thick and was considered rigid, as it was observed that higher film thicknesses were generally required to switch to "rubbery" behavior [43][44][45]. Moreover, any inclusion has to be quantitatively reversible to avoid "memory effects" and to avoid the need to resort to cleaning that could eventually modify/destroy the structure of the cavity formed into the film [19,20] or delaminate the film from the quartz surface [46]. In Figure 4A, the result of template inclusion is expressed as moles of template hosted during film formation at the Pt-quartz crystal (calculated as: moles of cMIP-moles of cNIP for each monomer) as a function of the different concentrations in solution of the template.…”

Application of electrodeposited piezo‐resistive polypyrrole for a pressure‐sensitive bruxism sensor

“…It was first synthesized in 1963 through pyrolysis of tetraiodopyrrole and subsequently tested for its electronic properties . Years later, conductive polypyrrole films have been synthesized for a variety of applications including molecularly imprinted polymer (MIP) sensors , copper protection , OLEDs , super‐capacitors , wearable electronic textiles , and pressure‐sensitive sensors .…”