Colorimetric and ultra-sensitive fluorescence resonance energy transfer determination of H2O2 and glucose by multi-functional Au nanoclusters.
Ultra-sensitive colorimetric determination of H2O2 is accomplished based on the intrinsic peroxidase-like activity of Au nanoclusters (AuNCs) stabilized by glutathione (GSH). The color change of 3,3,5,5-tetramethylbenzidine (TMB) catalyzed by AuNCs offers an indirect method to measure glucose. This sensing platform makes use of a dual optical signal change, including the color change in an aqueous solution under visible light illumination and an ultra-sensitive fluorescent assay arising from efficient fluorescence resonance energy transfer (FRET) between the AuNCs and oxidized TMB. The detection limits of H2O2 and glucose are 4.9 × 10(-13) M and 1.0 × 10(-11) M, respectively. In addition, enhanced fluorescence is observed from the AuNCs due to the use of ethanol which produces clear changes in the quantum yield and lifetime of the AuNCs. The quantum yield of AuNCs is enhanced from ∼12.5% as an isolated fluorophore to 38.9% in an AuNCs-ethanol complex. The enhanced fluorescence lowers the detection limits of H2O2 and glucose by 2 orders of magnitude compared to those attained from the original AuNCs.
Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Provincial University Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, China. hhwn09@163.com.
Qian
Q
Zhao
Shenna
S
Chen
Haowen
H
Huang
Lingyang
L
Zhang
Linqian
L
Wang
Fengping
F
Liu
Jian
J
Chen
Yunlong
Y
Zeng
Paul K
PK
Chu
D001560:Benzidines / Q000737:chemistry; D001786:Blood Glucose / Q000032:analysis*; D002863:Chromogenic Compounds / Q000737:chemistry; D003124:Colorimetry / Q000379:methods; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005978:Glutathione / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure
D001560:Benzidines; D001786:Blood Glucose; D002863:Chromogenic Compounds; C021758:3,3',5,5'-tetramethylbenzidine; D006046:Gold; D006861:Hydrogen Peroxide; D005978:Glutathione