title: An ultrasensitive hydrogen peroxide biosensor based on electrocatalytic synergy of graphene-gold nanocomposite, CdTe-CdS core-shell quantum dots and gold nanoparticles.
abstract: We first reported an ultrasensitive hydrogen peroxide biosensor in this work. The biosensor was fabricated by coating graphene-gold nanocomposite (G-AuNP), CdTe-CdS core-shell quantum dots (CdTe-CdS), gold nanoparticles (AuNPs) and horseradish peroxidase (HRP) in sequence on the surface of gold electrode (GE). Cyclic voltammetry and differential pulse voltammetry were used to investigate electrochemical performances of the biosensor. Since promising electrocatalytic synergy of G-AuNP, CdTe-CdS and AuNPs towards hydrogen peroxide was achieved, the biosensor displayed a high sensitivity, low detection limit (S/N=3) (3.2×10(-11) M), wide calibration range (from 1×10(-10) M to 1.2×10(-8) M) and good long-term stability (20 weeks). Moreover, the effects of omitting G-AuNP, CdTe-CdS and AuNP were also examined. It was found that sensitivity of the biosensor is more 11-fold better if G-AuNP, CdTe-CdS and AuNPs are used. This could be ascribed to improvement of the conductivity between graphene nanosheets in the G-AuNP due to introduction of the AuNPs, ultrafast charge transfer from CdTe-CdS to the graphene sheets and AuNP due to unique electrochemical properties of the CdTe-CdS, and good biocompatibility of the AuNPs for horseradish peroxidase. The biosensor is of best sensitivity in all hydrogen peroxide biosensors based on graphene and its composites up to now.
authors.affiliation: School of Chemical and Material Engineering, Jiangnan University, Wuxi, PR China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Gu
authors.forename: Shuping
authors.initials: S
authors.lastname: Yang
authors.forename: Zaijun
authors.initials: Z
authors.lastname: Li
authors.forename: Xiulan
authors.initials: X
authors.lastname: Sun
authors.forename: Guangli
authors.initials: G
authors.lastname: Wang
authors.forename: Yinjun
authors.initials: Y
authors.lastname: Fang
authors.forename: Junkang
authors.initials: J
authors.lastname: Liu
mesh_terms: D031215:Armoracia / Q000201:enzymology; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry; D002138:Calibration; D055664:Electrochemical Techniques / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000378:metabolism; D057230:Limit of Detection; D053761:Nanocomposites / Q000737:chemistry*; D045663:Quantum Dots; D013440:Sulfides / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D006046:Gold; D006108:Graphite; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D013691:Tellurium; C028337:cadmium telluride