A Target-Driven Self-Feedback Paper-Based Photoelectrochemical Sensing Platform for Ultrasensitive Detection of Ochratoxin A with an In₂S₃/WO₃ Heterojunction Structure

Abstract

Currently, developing versatile, easy-to-operate, and effective signal amplification strategies hold great promise in photoelectrochemical (PEC) biosensing. Herein, an ultrasensitive polyvinylpyrrolidone-treated In 2 S 3 /WO 3 (In 2 S 3 -P/WO 3 )-functionalized paper-based PEC sensor was established for sensing ochratoxin A (OTA) based on a target-driven self-feedback (TDSF) mechanism enabled by a dual cycling tactic of PEC chemical−chemical (PECCC) redox and exonuclease III (Exo III)-assisted complementary DNA. The In 2 S 3 -P/WO 3 heterojunction structure with 3D open-structure and regulable topology was initially in situ grown on Au nanoparticlefunctionalized cellulose paper, which was served as a universal signal transducer to directly record photocurrent signals without complicated electrode modification, endowing the paper chip with admirable anti-interference ability and unexceptionable photoelectric conversion efficiency. With the assistance of Exo III-assisted cycling process, a trace amount of OTA could trigger substantial signal reporter ascorbic acid (AA) generated by the enzymatic catalysis of alkaline phosphatase, which could effectively provoke the PECCC redox cycling among the tris(2-carboxyethyl)phosphine acid, AA, and ferrocenecarboxylic at the In 2 S 3 -P/WO 3 photoelectrode, initiating TDSF signal amplification. Based on the TDSF process induced by the Exo III-assisted recycling and PECCC redox cycling strategy, the developed paper-based PEC biosensor realized ultrasensitive determination of OTA with persuasive selectivity, high stability, and excellent reproducibility. It is believed that the proposed paper-based PEC sensing platform exhibited enormous potential for the detection of other targets in bioanalysis and clinical diagnosis.

Molecular Imprinted Poly(2,5-benzimidazole)-Modified VO2–CuWO4 Homotype Heterojunction for Photoelectrochemical Dopamine Sensing

“…Dopamine (DA) as a critical neurotransmitter plays an important role in normal human life and controls the metabolism and functioning of the central nervous, renal, and hormone systems. − Abnormal (low) levels of DA can cause neurological disorders such as hypertension, schizophrenia, Parkinson’s, Alzheimer’s, HIV, and attention-deficit hyperactivity disorder, while high DA levels can make people addicted. − Thus, there is an urgent demand to develop a robust, rapid, sensitive, and selective strategy for DA monitoring for disease prevention and treatment. Various analytical and bioanalytical methods, including colorimetric method, surface plasmon resonance, ion-exchange chromatography, fluorescence, high-performance liquid chromatography, chemiluminescence, electrochemiluminescence, and electrochemical method, have been developed to monitor DA in different media. ,− High signal background (low sensitivity) and bulky instruments are significant challenges in these methods. , Alternatively, increasing efforts have been focused on photoelectrochemical (PEC) assays as an attractive frontier in state-of-the-art analysis because of their advantages, such as low background signals and separation of excitation and detection signals. − PEC sensors are consisting of photoelectrically active support such as functional semiconductors (SCs) and quantum dots, as well as recognition agents such as aptamer, antibodies, protein, and so on. − Considering the inherent disadvantages of antibodies and aptamers such as low stability, high cost, photoelectric inactivity, and complex operation, developing novel recognition agents are very vital. − In addition, the strong oxidizability of OH radicals generated in PEC oxidation causes photocorrosion and severe reduction of selectivity. , Therefore, for designing a robust PEC sensor, the selection of a stable, biocompatible, photoelectrically active, and cost-effective recognition element of high electron mobility, excellent chemical and thermal stability, and photoelectrically active support is of high importance …”

Molecularly Imprinted Polymer Functionalized Bi2S3/Ti3C2TX MXene Nanocomposites for Photoelectrochemical/Electrochemical Dual-Mode Sensing of Chlorogenic Acid

“…Generally speaking, the core element of the sensor includes materials and recognition probes. For a PEC signal, it is efficient photoelectric conversion based on photosensitive material [13], i.e., hollow In 2 O 3 -In 2 S 3 [14], AuNPs/Cs 3 Bi 2 Br 9 QDs/BiOBr [15] and In 2 S 3 /WO 3 heterojunction [16] presented efficient PEC performance for biosensors, whereas for an EC signal, suitable electrocatalytic materials can obtain a sensing model with high sensitivity [17], such as Au-Based nanocomposites [18], two-dimensional nanomaterials [19] and metal-organic frameworks (MOFs) [20]. Therefore, the selection of materials with high photosensitivity, conductivity and electrocatalytic properties is crucial to the development of PEC-EC dual-mode sensors for the ideal signals acquisition.…”

Polymer dots synergized with a NiO hole transporting layer and poly(amido amine) dendrimer: toward sensitive photocathodic detection of tyrosinase level in serum

“…Photoelectrochemical (PEC) bioanalysis is a rapidly developing methodology for sensitive biomolecule detection with a fast response, low background and high sensitivity. [11][12][13][14][15][16] In comparison with the well-studied photoanodic bioanalysis, [17][18][19][20][21][22][23][24][25][26] serious consideration of p-type light-harvesting materials for photocathodic bioanalysis is relatively recent. [27][28][29][30][31] Nevertheless, because of their desirable properties such as higher stability than the anodic system and superior antiinterference capability against reductive substances in actual biological samples, exploration in this direction is gaining strong momentum.…”