Determination of the activity of hydrogen peroxide scavenging by using blue-emitting glucose oxidase–stabilized gold nanoclusters as fluorescent nanoprobes and a Fenton reaction that induces fluorescence quenching

Abstract

The authors describe a rapid and sensitive method for the determination of the activity of scavenging hydrogen peroxide in which glucose oxidase-stabilized gold nanoclusters (AuNCs) were employed as a fluorescent nanoprobe. The AuNCs are synthesized by a biomineralization process and display an intense blue fluorescence peaking at 450 nm and a quantum yield of 1.1% under 360-nm excitation. The Fenton reaction induces quenching of fluorescence, and this effect can be used to determine H 2 O 2 in the 0.5 to 10 μmol⋅L −1 concentration range. The substances displaying H 2 O 2 scavenging activity prevent quenching and thus restore fluorescence. The intensity of restored fluorescence is directly related to the H 2 O 2 scavenging activity of the antioxidant. The method was applied to the determination of the H 2 O 2 scavenging activity of the model antioxidants ascorbic acid and tartaric acid which gave IC 50 values of 7.4 and 19.1 μmol⋅L −1 , respectively.

Fluorescent Enzymatic Sensor Based Glucose Oxidase Modified Bovine Serum Albumin‐Gold Nanoclusters for Detection of Glucose

“…To evaluate the hydrogen peroxide evolution effect on BSA‐AuNCs, different concentration of 30 % H 2 O 2 (0.096–0.5 mM) is added and the fluorescence response is noted. The result reveal that the peroxide formation degrades the Au−S bond in gold nanocluster thereby turn‐off the fluorescence of synthesised BSA‐AuNCs [36] . The fluorescence response spectra and linear response plot of BSA‐AuNCs with different concentration of hydrogen peroxide with R 2 at 0.9882 and intercept at 0.05 is given in S8.…”

“…The result reveal that the peroxide formation degrades the AuÀ S bond in gold nanocluster thereby turn-off the fluorescence of synthesised BSA-AuNCs. [36] The fluorescence response spectra and linear response plot of BSA-AuNCs with different concentration of hydrogen peroxide with R 2 at 0.9882 and intercept at 0.05 is given in S8. A, B.…”

Fluorescence Turn-On Antioxidant Recognition by Interface-Mediated Radical Termination ofl-Cysteine-Capped Gold Nanoclusters

“…A fluorescence “turn on” approach, on the other hand, can often provide better detection results and deliver more delicate signal controls . For instance, a AuNC fluorescence turn on approach has been demonstrated for the detection of ascorbic acid, where the presence of antioxidants can protect the AuNC fluorescence from ROS induced quenching. , However, AuNC based fluorescence turn on ROS sensing is still relatively rare due to difficulties in analyte selective electron transfer process design and correspondent material preparation.…”

Convenient and sensitive colorimetric detection of melamine in dairy products based on Cu(ii)-H2O2-3,3′,5,5′-tetramethylbenzidine system

“…[31][32][33][34] Among them, Fenton reaction as an inorganic reaction, has attracted signicant interest due to its unique characteristic of simplicity, rapidness and convenience. 33,[35][36][37] Among various Fenton reaction based methods for bioanalysis, colorimetric assay that only utilized the oxidation of the hydroxyl radicals ($OH) produced by the Fenton reaction, has attracted signicant interest due to its rapidness, obvious colour change, no need to use expensive analytical instruments and simple readout with the naked eye. The reaction between 3,3 0 ,5,5 0 -tetramethylbenzidine (TMB) and hydrogen peroxide (H 2 O 2 ) was one of the most widely used colorimetric reactions for the detection of various targets including glucose, [38][39][40] histidine and cysteine, 41 cholesterol, 42 Cu 2+ , 33,43 UA, 44,45 glyphosate, 46 and cancer cells.…”