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

In the presence of thioglycolic acid (TGA) and under the catalysis of Fe 3+ , 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 H 2 O 2 in human serum. TGA is the key factor for fluorescence response toward H 2 O 2 by N-GQDs and the mechanism is H 2 O 2 reacts speedily with TGA under the catalysis of Fe 3+ , and produces intermediate of superoxide anions ( O 2 − ), 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 H 2 O 2 has been improved by nearly 5-folds. Under the optimum conditions, F λ=580nm / F λ=440nm has a good linear relationship with the concentration of H 2 O 2 and the detection limit of H 2 O 2 is 0.46 μmol/L with 3.5% RSD. The established sensor platform has been successfully used for probing H 2 O 2 in human serum with satisfactory results. The superior performance of the probe lies in its high selectivity and can be directly employed in detecting H 2 O 2 in serum samples without any sample pretreatment procedures.