Light-Controlled Bioelectrochemical Sensor Based on CdSe/ZnS Quantum Dots

Abstract

This study reports on the oxygen sensitivity of quantum dot electrodes modified with CdSe/ZnS nanocrystals. The photocurrent behavior is analyzed for dependence on pH and applied potential by potentiostatic and potentiodynamic measurements. On the basis of the influence of the oxygen content in solution on the photocurrent generation, the enzymatic activity of glucose oxidase is evaluated in solution. In order to construct a photobioelectrochemical sensor which can be read out by illuminating the respective electrode area, two different immobilization methods for the fixation of the biocatalyst have been investigated. Both covalent cross-linking and layer-by-layer deposition of GOD by means of the polyelectrolyte polyallylamine hydrochloride show that a sensor construction is possible. The sensing properties of this type of electrode are drastically influenced by the amount and density of the enzyme on top of the quantum dot layer, which can be advantageously adjusted by the layer-by-layer technique. By depositing four bilayers [GOD/PAH](4) on the CdSe/ZnS electrode, a fast-responding sensor for the concentration range of 0.1-5 mM glucose can be prepared. This study opens the door to multianalyte detection with a nonstructured sensing electrode, localized enzymes, and spatial read-out by light.

Plasmonic AuNP/g-C3N4Nanohybrid-based Photoelectrochemical Sensing Platform for Ultrasensitive Monitoring of Polynucleotide Kinase Activity Accompanying DNAzyme-Catalyzed Precipitation Amplification

“…The photoelectrochemical (PEC) sensing approach is a newly emerged yet dynamically developing technique for various biological assays including antigens or antibodies, 1-3 nucleic acids, 4,5 proteins, 6 and cell. 7,8 Evolved from the traditional electrochemical detection method, the PEC-based sensing strategy can preserve the essential benefits of the former in sensitivity, robustness, broad applicability, and suitability to automation.…”

Fabrication of Photoelectrochemical Glucose Biosensor in Flow Injection Analysis System Using ZnS/CdS‐Carbon Nanotube Nanocomposite Electrode

“…Recently, semiconductor nanomaterials (especially quantum dots, QDs) have attracted much attention in the development of electrochemical, photoelectrochemical and optical sensors and biosensors. Since they have special electronic and photophysical properties such as broad adsorption, narrow emission and high quantum yield [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][24][25][26][27][28].…”

“…Following, formed anodic or cathodic photocurrent is monitored dependent on analyte concentration. According to this mechanism, photoelectrochemical sensors and biosensors for the sensitive detection of biologically, environmentally, medicinally important molecules have been fabricated [2][3][4][5][6][7][8].…”

Ultrasensitive photoelectrochemical immunoassay through tag induced exciton trapping

“…As a highly sensitive detection methodology, PEC sensing is a newly developed technology which has drawn growing interest in many fields, such as environmental monitoring and bioanalysis [13][14][15][16][17][18][19][20][21]. Owing to the separation of excitation signal and detection signal, PEC sensing strategy has plenty of advantages such as low background, low potential different from electrochemiluminescence analysis, which leads to a good analytical performance.…”