Boron- and Phenyl-Doped Graphitic Carbon Nitride (g-C₃N₄) Nanosheets for Colorimetric Detection of Hydrogen Peroxide in Soaked Foods.

Abstract

Boron- and phenyl-doped graphitic carbon nitride nanosheets (BPCN NSs) were prepared by thermal polymerization of cyanamide with 3-aminobenzeneboronic acid followed by ultrasonic exfoliation. BPCN NSs exhibited enhanced peroxidase-like activity and catalyzed the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and o-phenylenediamine by H₂O₂. A simple sensitive colorimetric senor was developed for H₂O₂ by utilizing TMB as the substrate and BPCN NSs as enzyme mimetic. The linear relations between the absorbance and H₂O₂ concentration over the range from 0 to 280 μmol L^-1 and from 280 to 1000 μmol L^-1 were obtained with the limit of detection of 1.0 μmol L^-1 according to the 3σ rule. The colorimetric sensor was applied for the detection of H₂O₂ residue in simulated soaked foods with satisfied results. Finally, the portable test kits for H₂O₂ were prepared and applied for the semi-quantitative assay of H₂O₂ residues in soaked chicken feet.