In Situ Modification of a Semiconductor Surface by an Enzymatic Process: A General Strategy for Photoelectrochemical Bioanalysis

Abstract

Usually, the photoelectrochemical (PEC) bioanalysis necessitates ready photoactive materials as signal sources to convert the specific biological events into electrical signals. Herein, the first PEC bioanalysis without the necessity of ready visible-light-active species was demonstrated. We use an enzyme catalytic process to couple with the unique surface chemistry of semiconductive nanocrystalline, whereby its electronic properties could be modified spontaneously during the enzymatic reaction. Specifically, the enzymatic hydrolysis of ascorbic acid 2-phosphate by alkaline phosphatase is allowed to interact on the TiO2 nanoparticles (NPs) matrix. PEC tests reveal that the self-coordination of the biocatalyzed enediol-ligands onto the undercoordinated surface defect sites would in situ form a ligand-to-metal charge transfer (CT) complex, endowing the inert semiconductor with strong absorption bands in the visible region, and hence underlying a novel and general PEC bioanalysis strategy.

Using G-Quadruplex/Hemin To “Switch-On” the Cathodic Photocurrent of p-Type PbS Quantum Dots: Toward a Versatile Platform for Photoelectrochemical Aptasensing

“…The introduction of PEC labels/indicators and generating electron donors/acceptors and/or steric hindrance are the widest used approaches available. [4][5][6][7][9][10][11][12]15 Thus, to design novel photoelectrodes for advanced PEC detection with innovative signalling mechanism would obviously be desirable.The true self-operating photocathode of p-type nickel oxide electrode utilizing a freebase porphyrin or erythrosine B as a sensitizer was firstly introduced by Lindquist et al, 18 whose pioneering work has generated renewed interest in solar cells 19 and PEC water splitting 20,21 in recent years. Photocathode may provide a viable strategy for advanced PEC bioanalysis applications.…”

“…[1][2][3][4][5][6][7] Such detection system could provide excellent sensitivity due to the totally different forms of energy for excitation and detection. Due to its attractive potential in future biomolecular detection, currently, enormous effort has been devoted to its exploitation and substantial advances have been achieved.…”

Novel photoelectrochemical hydrogen peroxide sensor based on hemin sensitized nanoporous NiO based photocathode

“…So, the photoelectrochemically active materials play a crucial role in the performance of the as developed PEC sensors. To the best of our knowledge, most of the photoelectrochemically active materials are mainly concentrated on photoanodes made up of n-type semiconductors or sensitized n-type semiconductors, such as CdS quantum dots (QDs) [14,15], CdSe/ZnS [16], TiO 2 [17], or sensitized TiO 2 [18][19][20][21]. However, because of the inherent photoinduced hole oxidation reaction at the photoanode/electrolyte surface, it is still highly demanding and challenging to develop highly selective PEC sensing system with innovative signaling mechanism for the detection of small biomolecules.…”

Electrochemical hydrogen peroxide sensor based on a glassy carbon electrode modified with nanosheets of copper-doped copper(II) oxide

“…They have potential applications in electronics, catalysis and bioanalysis. In addition, these unique properties of nanostructured materials [2][3][4][5][6][7][8][9] facilitate the discovery of new applications, which can not be achieved with the use of bulk materials. One such area has involved the development of electrochemical sensors [10][11][12], especially those using inexpensive nanoparticles, such as copper [13], nickel [14], and their oxides [15].…”