Cathode Photoelectrochemical Immunosensing Platform Integrating Photocathode with Photoanode

Abstract

Generally, photoanode-based photoelectrochemical immunoassay possesses obvious photocurrent response and lower detection limit for ideal sample detection, but it has the inherent imperfection of poor anti-interference capability for real sample detection. Photocathode-based immunoassay can well avoid the intrinsic drawback of photoanode-based immunoassay, but it has low photocurrent response resulting in less good sensitivity. Herein, a promising new cathode photoelectrochemical immunosensing platform integrating photocathode with photoanode was reported for accurate and sensitive detection of biomarkers. In this proposal, prostate-specific antigen (PSA, Ag) was chosen as a model of target analyte to exhibit the analytical performances of this platform. TiO/CdS:Mn hybrid structure modified indium-tin oxide (ITO) electrode served as photoanode, whereas CuInS microflowers modified ITO electrode was selected as photocathode. The transducer elements of PSA antibody (Ab) were modified on photocathode to fabricate a label-free cathode immunosensing electrode. The proposed immunosensing platform possesses two distinct advantages simultaneously. First, it has good anti-interference capability for the detection of real biological samples, since the biorecognition events occurred on photocathode. Second, the photoelectrochemical system owns evident photocurrent response and low detection limit for target Ag detection thanks to the introduction of the photoanode. Moreover, the proposed immunosensing platform also exhibits good specificity, reproducibility, and stability, and meanwhile it opens up a new horizon to construct other kinds of photoelectrochemical biosensors.

Preparation and characterization of 0D Au NPs@3D BiOI nanoflower/2D NiO nanosheet array heterostructures and their application as a self-powered photoelectrochemical biosensing platform

“…12,21,22 In other words, p-type semiconductors are more stable than n-type semiconductors toward oxidation reactions. 23 As a popular p-type semiconductor, NiO (nickel oxide) has been widely used in the eld of sensors, catalyzers and solar cells due to its good stability, unique electrochemical performance and excellent catalytic properties. 20,24 BiOI (bismuth oxyiodide) is an ideal p-type photosensitizer with a narrow band gap ($1.7 eV) that possesses a wide visible light absorption range.…”

Sulfur-Doped Graphene-Based Immunological Biosensing Platform for Multianalysis of Cancer Biomarkers

“…Compared with the traditional single-analyte immunosensor, − the simultaneous multianalysis is more accurate and precise in clinical applications because it can quantitatively detect a panel of biomarkers in a single run with improved diagnostic specificity . Moreover, the multianalysis of cancer biomarkers can simplify the analytical procedure, enhance the detection throughput, and decrease the detection cost .…”

Hybrid PbS Quantum Dot/Nanoporous NiO Film Nanostructure: Preparation, Characterization, and Application for a Self-Powered Cathodic Photoelectrochemical Biosensor

“…With the ever-growing demand for future sensing, there have been continuous efforts to exploit novel techniques with ingenious signaling strategies. − Self-powered sensors, a rapidly developing concept, eliminate the common necessity of the external power sources and permit detection without the application of any voltage bias between the cathode and anode. , Such unique characteristics, along with the simple fabrication process, miniature size, and low cost, make them promising candidates for the diagnosis of human disease, especially as battery-less portable devices. − Using semiconductors, a self-powered photoelectrochemical (PEC) biosensor is a newly developed and promising method that offers good sensitivity, portability, and the possibility of miniaturization and integration. − Currently, because of the development of nanoscience and nanotechnology, more interest has been focused on the design and applications of functional semiconductor species for innovative self-powered PEC biosensors. ,− In the quest for achieving the desired performance and proper stability, judiciously designed heterostructures consisting of two semiconductors are being considered as favorite photoelectrode schemes. − The existing literature has also demonstrated different heterostructures as effective tools for extending the absorbance to the visible region and improving photogenerated separation of charge carriers with increased lifetimes. − However, consistently, appropriate band gap, proper band edge alignment with each other and with the redox potential of the electron donor/acceptor, minimal lattice mismatch, high stability, and ideal integration with the biorecognition events are the fundamental requirements for the construction of an efficient PEC biosensor system. − To date, reported heterostructures for PEC biosensing have mainly focused on the coupling of various n-type TiO 2 species [nanoparticles (NPs), nanotubes (NTs), or nanowires (NWs) with n-type Cd-chalcogenide (S, Se, and Te) quantum dots (QDs)], leading to the development of different photoanodes. , For self-powered PEC biosensing, significantly, Zhang et al reported a self-powered sensing platform using Ni­(OH) 2 /CdS/TiO 2 , a hemin–graphene nanocomposite, and glucose as the photoanode, the photocathode, and a model analyte, respectively…”

“…In spite of their fascinating characteristics, study of this domain lags greatly. Recently, p-type BiOI and CuInS 2 were used to construct the cathodic PEC aptasensor and cathodic PEC immunoassay, respectively. With respect to the heterojunction photocathodes, at present, only limited work exploited the use of p-type species for the construction of a p–n heterojunction comprised of, e.g., p-type BiOI and n-type TiO 2 proposed by our group. , Obviously, novel p-type-based heterostructures and their smooth application in efficient self-powered PEC bioanalysis are highly desirable.…”