Nitrogen-Doped Carbon Nanoflowers Decorated with PtNi Nanoparticles for Colorimetric Detection of Total Antioxidant Capacity
Yan-Wen Mao, Jiaqi Li, Rui Zhang, Ai‐Jun Wang, Jiu‐Ju Feng
Abstract
A total antioxidant capacity (TAC) assay plays an essential role in evaluating antioxidant behaviors. It mainly involves examining the dosages of antioxidants such as ascorbic acid (AA), while TAC can be measured by nanozyme with peroxidase-like activity. Herein, nitrogen-doped carbon nanoflowers decorated with uniform PtNi nanoparticles (PtNi/NCFs) were fabricated by a simple pyrolysis strategy. The obtained PtNi/NCFs showed high peroxidase-mimicking activity to catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation by generating rich hydroxyl radicals (·OH) in the H 2 O 2 system. By virtue of the PtNi/NCFs nanozyme, a visual colorimetric sensor was developed for assays of H 2 O 2 and AA. The limits of detection were as low as 45.3 and 0.94 μM for determination of H 2 O 2 and AA with linear ranges of 100–1000 and 1.0–20.0 μM, respectively. Moreover, such sensor was also successfully employed to detect AA and H 2 O 2 in real tablets and juices. The PtNi/NCFs nanozyme holds great potential for practical applications.