Gold Nanocluster-Assisted Fluorescent Detection for Hydrogen Peroxide and Cholesterol Based on the Inner Filter Effect of Gold Nanoparticles

Abstract

We developed a simple, sensitive inner filter effect (IFE)-based fluorescent assay for sensing H2O2 and cholesterol. In the process, poly(vinylpyrrolidone)-protected gold nanoparticles (PVP-AuNPs) and fluorescent BSA-protected gold nanoclusters (BSA-AuNCs) were used as an IFE absorber/fluorophore pair. PVP-AuNPs can be a powerful absorber to influence the emission of the fluorophore, BSA-AuNCs, in the IFE-based fluorescent assays. That is due to the high extinction coefficient of AuNPs and the complementary overlap between the surface plasmon resonance (SPR) absorption of PVP-AuNPs and the excitation of BSA-AuNCs. The PVP-Au seeds, produced by directly mixing PVP with HAuCl4, were able to catalyze H2O2 to enlarge AuNPs. The SPR absorption of PVP-AuNPs was enhanced with an increased concentration of H2O2 and, subsequently, induced significant fluorescence quenching of BSA-AuNCs. The IFE-based fluorescent assay enabled the detection of H2O2 and generation of H2O2 in the presence of O2/cholesterol and cholesterol oxidase (ChOx) by the fluorescence response of BSA-AuNCs. The present IFE-based approach can detect H2O2 ranging from 1 to 100 μM with a detection limit of 0.8 μM and cholesterol ranging from 1 to 100 μM with a detection limit of 1.4 μM.

Possibilities and Challenges for Quantitative Optical Sensing of Hydrogen Peroxide

“…Heavy metals are frequently used as base for nanoparticles, such as silver [76][77][78][79][80], gold [81][82][83][84][85][86], cadmium, zinc or tellurium [87,88]. Silver nanoparticles (Ag-NP) in general have a broad field of application, as they are antibacterial, antiviral, and antifungal.…”

Highly sensitive on-site detection of glucose in human urine with naked eye based on enzymatic-like reaction mediated etching of gold nanorods

“…The successful visual detection of urine glucose in original sample show its applicability for on-site identification of the healthy status of a diabetes patient. Finally, the GNRs-based method for sensitive detection of H 2 O 2 can be used for other H 2 O 2 -based sensing applications, (Chang and Ho, 2015;Liu et al, 2014;Wang et al, 2012;Yang and Tseng 2016) such as GOx-based immunoassay as shown in Scheme S1 (Supplementary Information).…”

Electrochemical Detection of Hydrogen Peroxide by Inhibiting the p-Benzenediboronic Acid-Triggered Assembly of Citrate-Capped Au/Ag Nanoparticles on Electrode Surface

“…Thus, the colorimetric examples were expected to re-create existing platforms with improved sensitivity. By simply incorporating the colorimetric principle or technique into another field, new achievements were produced recently [14,15,16,17,18]. For example, based on the high quenching efficiency of dispersed but not aggregated Au NPs on the fluorescence of organic dyes or quantum dots (denoted as the efficient inner filter effect), visual and fluorescent sensors could be developed [14,15,16].…”

“…By simply incorporating the colorimetric principle or technique into another field, new achievements were produced recently [14,15,16,17,18]. For example, based on the high quenching efficiency of dispersed but not aggregated Au NPs on the fluorescence of organic dyes or quantum dots (denoted as the efficient inner filter effect), visual and fluorescent sensors could be developed [14,15,16]. Furthermore, Wei et al first suggested that the target-induced aggregation of Ag NPs in solution could be facilely initiated on the solid-liquid surface, which thus converted a liquid-phase Hg 2+ colorimetric assay into an electrochemical analysis with improved sensitivity [18].…”