Quantifying H2O2 by ratiometric fluorescence sensor platform of N-GQDs/rhodamine B in the presence of thioglycolic acid under the catalysis of Fe3+

Abstract

In the presence of thioglycolic acid (TGA) and under the catalysis of Fe3+, a simple, rapid, sensitive, selective and effective ratiometric fluorescence sensor platform based on the mixed physically blue nitrogen-doped graphene quantum dots (N-GQDs) as probe signals and orange rhodamine B as internal standard signals has been constructed for analysis of H2O2 in human serum. TGA is the key factor for fluorescence response toward H2O2 by N-GQDs and the mechanism is H2O2 reacts speedily with TGA under the catalysis of Fe3+, and produces intermediate of superoxide anions (O2−), which accepts electrons from N-GQDs, and generates graphene oxide, causing the fluorescence quench of N-GQDs. Compared with N-GQDs probe, the sensitivity of the ratiometric fluorescence sensor platform of N-GQDs/rhodamine B for analysis of H2O2 has been improved by nearly 5-folds. Under the optimum conditions, Fλ=580nm/Fλ=440nm has a good linear relationship with the concentration of H2O2 and the detection limit of H2O2 is 0.46 μmol/L with 3.5% RSD. The established sensor platform has been successfully used for probing H2O2 in human serum with satisfactory results. The superior performance of the probe lies in its high selectivity and can be directly employed in detecting H2O2 in serum samples without any sample pretreatment procedures.