title: Gold nanoclusters as switch-off fluorescent probe for detection of uric acid based on the inner filter effect of hydrogen peroxide-mediated enlargement of gold nanoparticles.
abstract: Herein we report a novel switch-off fluorescent probe for highly selective determination of uric acid (UA) based on the inner filter effect (IFE), by using poly-(vinylpyrrolidone)-protected gold nanoparticles (PVP-AuNPs) and chondroitin sulfate-stabilized gold nanoclusters (CS-AuNCs) as the IFE absorber/fluorophore pair. In this IFE-based fluorometric assay, the newly designed CS-AuNCs were explored as an original fluorophore and the hydrogen peroxide (H2O2) -driven formed PVP-AuNPs can be a powerful absorber to influence the excitation of the fluorophore, due to the complementary overlap between the absorption band of PVP-AuNPs and the emission band of CS-AuNCs. Under the optimized conditions, the extent of the signal quenching depends linearly on the H2O2concentration in the range of 1-100μM (R2=0.995) with a detection limit down to 0.3μM. Based on the H2O2-dependent fluorescence IFE principle, we further developed a new assay strategy to enable selective sensing of UA by using a specific uricase-catalyzed UA oxidation as the in situ H2O2generator. The proposed uricase-linked IFE-based assay exhibited excellent analytical performance for measuring UA over the concentration ranging from 5 to 100μM (R2=0.991), and can be successfully applied to detection of UA as low as 1.7μM (3σ) in diluted human serum samples.
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Phytochemical R&D of Hunan Province, Hunan Normal University, Changsha 410081, China.
authors.forename: Hongchang
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081, China. Electronic address: binguo@hunnu.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Guo
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wei
authors.affiliation: Key Laboratory of Phytochemical R&D of Hunan Province, Hunan Normal University, Changsha 410081, China. Electronic address: dr-chenpo@vip.sina.com.
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081, China.
authors.forename: Youyu
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D002809:Chondroitin Sulfates / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011205:Povidone / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D014527:Uric Acid / Q000097:blood*
chemical_list: D005456:Fluorescent Dyes; D014527:Uric Acid; D006046:Gold; D002809:Chondroitin Sulfates; D006861:Hydrogen Peroxide; D011205:Povidone
keywords: Chondroitin sulfate-stabilized gold nanoclusters (CS-AuNCs); Fluorescence; Hydrogen peroxide; Inner filter effect; Poly-(vinylpyrrolidone)-protected gold nanoparticles (PVP-AuNPs); Uric acid