Electropolymerization-Induced Positively Charged Phenothiazine Polymer Photoelectrode for Highly Sensitive Photoelectrochemical Biosensing

Abstract

Exploring the fabrication of an electrode with high photoelectric conversion efficiency and abundant functional groups for ideal photoelectrochemical (PEC) sensor development is highly urgent but faces a significant challenge. Herein we report an electropolymerization strategy for the preparation of phenothiazine polymeric film on an indium tin oxide (ITO) surface (PPT/ITO), within only a few seconds, and monomers. The fabricated PPT/ITO electrode possessed excellent stability and abundant quaternary ammonium salt groups for developing a highly sensitive PEC sensor through electrostatic binding with negatively charged materials. In this context, a CdS QDs-functionalized PPT/ITO electrode (CdS/PPT/ITO) was proposed and applied to the analysis of chlorpyrifos, used as a model target organophosphorous pesticide (OP). The thiocholine generated from acetylcholinesterase (AChE)-induced catalyzed hydrolysis of acetylthiocholine (ATCh) efficiently directed CdS QDs away from PPT/ITO via electrostatic repulsion, subsequently decreasing PEC current, whereas chlorpyrifos prohibited the generation of thiocholine through inhibiting AChE activity. As compared to the case where chlorpyrifos is absent, significantly enhanced PEC current is determined and is proportional to chlorpyrifos amounts. Thus, the developed CdS/PPT/ITO-based PEC sensor achieved excellent chlorpyrifos biosensing with improved sensitivity down to approximately ng/mL level with good specificity. We envision the proposed strategy will provide a new path to conveniently fabricate photoelectrodes possessing high performance, which will have more useful applications in PEC sensing.

Ultrasensitive Photoelectrochemical Assay for DNA Detection Based on a Novel SnS2/Co3O4 Sensitized Structure

“…The rapid and sensitive detection of specific sequences of DNA has been playing an indispensable role in the fields of diagnosis of genetic diseases, virus assays, early screening of cancers, and so forth. − Since a trace amount of DNA exists in the biological samples, it is hence of vital importance to present a technique for DNA determination with high sensitivity and accuracy. , Numerous analysis systems including electrochemistry, , electrochemiluminescence, fluorescence, , photoelectrochemistry, , and so on have been proposed for DNA detection. Among these, photoelectrochemical (PEC) assay, a flourishing analytical tool, has drawn substantial attention on account of handy operation, low cost, high sensitivity, and low background noise. − Therefore, designing a smart PEC biosensor for rapidly and sensitively detecting DNA is required.…”

Polymer Based Functional Materials: A New Generation Photo‐active Candidate for Electrochemical Application

“…The resulted quaternary ammonium salt groups were used to develop the sensor‐based material via electrostatic binding (negatively charged substrates). The group also demonstrated the sensing applicability of the polymer‐based phenothiazine material by using assays of assaying chlorpyrifos spiked in cabbage extract and lake water [137]. The CdS quantum dots functionalized Phenothiazine polymer photoelectrode was used as the sensor prototype since the phenothiazine polymeric film provided positive groups to absorb the CdS quantum dots and channeling as an effective charge transporter that enhances the photoelectrochemical performances [138].…”

Electrochemical detection of methyl-paraoxon based on bifunctional cerium oxide nanozyme with catalytic activity and signal amplification effect

“…To solve this problem, rapid detection methods were designed and constructed for on-site analysis of MP as emerging technologies. Various on-site analysis methods based on the inhibition of bioenzymes activity, like acetylcholinesterase, have been applied for the rapid detection of MP [ 21 , 22 ]. Due to high specificity, sensitivity, simplicity, and efficiency, the enzyme-based sensing technique has become the mainstream of rapid detection.…”