In Situ Growth Reaction on Photoelectrodes of Single-Atom Fe Incorporated Bi₄O₅I₂: A General Photoelectrochemical Immunoassay Toward Sensitive Protein Analysis

Abstract

As one of the interesting signaling mechanisms, the in situ growth reaction on a photoelectrode has proven its powerful potential in photoelectrochemical (PEC) bioanalysis. However, the specific interaction between the signaling species with the photoactive materials limits the general application of the signal mechanism. Herein, on the basis of an in situ growth reaction on a photoelectrode of single-atom-based photoactive material, a general PEC immunoassay was developed in a split-type mode consisting of the immunoreaction and PEC detection procedure. Specifically, a single-atom photoactive material that incorporates Fe atoms into layered Bi 4 O 5 I 2 (Bi 4 O 5 I 2 −Fe SAs) was used as a photoelectrode for PEC detection. The sandwich immunoreaction was performed in a well of a 96-well plate using Ag nanoparticles (Ag NPs) as signal tracers. In the PEC detection procedure, the Ag + converted from Ag NPs were transferred onto the surface of the Bi 4 O 5 I 2 − Fe SAs photoelectrode and thereafter AgI was generated on the Bi 4 O 5 I 2 −Fe SAs in situ to form a heterojunction through the reaction of Ag + with Bi 4 O 5 I 2 −Fe SAs. The formation of heterojunction greatly promoted the electro-hole separation, boosting the photocurrent response. Exemplified by myoglobin (Myo) as the analyte, the immunosensor achieved a wide linear range from 1.0 × 10 −11 to 5.0 × 10 −8 g mL −1 with a detection limit of 3.5 × 10 −12 g mL −1 . This strategy provides a general PEC immunoassay for disease-related proteins, as well as extends the application scope of in situ growth reaction in PEC analysis.

Enzymatically Mediated In Situ Generation of Z-Scheme Bi2S3/Bi2MoO6 Heterojunction-Based Organic Photoelectrochemical Transistor for METTL3/METTL14 Detection

“…Photoelectrochemical (PEC) biosensors are an integrated tool based on the combination of photoelectrochemical processes and biorecognition processes that can be used to convert analyses into recognizable signals through molecular interactions . PEC biosensors mainly include two processes, one is photoelectric conversion of photoactive materials, and the other is conversion of biochemical or chemical information into electrical signals by biomolecules through various mechanisms. , To date, various photoelectric biosensor strategies have been proposed for the detection of the METTL3/METTL14 complex enzymes. For example, using MoSe 2 /BiOI as a photoactive material, the METTL3/METTL14 protein was detected by a catalytic hairpin self-assembly and alkaline phosphatase (ALP)-catalyzed L -ascorbic acid-2-phosphate (AAP) in situ generation of electron donor AA signal amplification strategy .…”