title: Visible light induced photoelectrochemical biosensing based on oxygen-sensitive quantum dots.
abstract: A visible light induced photoelectrochemical biosensing platform based on oxygen-sensitive near-infrared quantum dots (NIR QDs) was developed for detection of glucose. The NIR QDs were synthesized in an aqueous solution, and characterized with scanning electron microscopy and X-ray photoelectron spectroscopy. The as-prepared NIR QDs were employed to construct oxygen-sensitive photoelectrochemical biosensor on a fluorine-doped tin oxide (FTO) electrode. The oxygen dependency of the photocurrent was investigated at as-prepared electrode, which demonstrated the signal of photocurrent is suppressed with the decreasing of oxygen. Coupling with the consumption of oxygen during enzymatic reaction, a photoelectrochemical strategy was proposed for the detection of substrate. Using glucose oxidase (GOx) as a model enzyme, that is, GOx was covalently attached to the surface of CdTe QDs, the resulting biosensor showed the sensitive response to glucose. Under the irradiation of visible light of a wavelength at 505 nm, the proposed photoelectrochemical method could detect glucose ranging from 0.1 mM to 11 mM with a detection limit of 0.04 mM. The photoelectrochemical biosensor showed a good performance with high upper detection limit, acceptable stability and accuracy, providing an alternative method for monitoring biomolecules and extending the application of near-infrared QDs.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Bao
authors.forename: Jianping
authors.initials: J
authors.lastname: Lei
authors.forename: Wenwen
authors.initials: W
authors.lastname: Tu
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D055664:Electrochemical Techniques / Q000295:instrumentation; D004566:Electrodes; D005947:Glucose / Q000032:analysis; D008027:Light; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes; D045663:Quantum Dots
chemical_list: D005947:Glucose; D010100:Oxygen