Fe(iii)-based coordination polymernanoparticles: peroxidase-like catalytic activity and their application to hydrogen peroxide and glucose detection

Abstract

Fe(III)-based coordination polymer nanoparticles (FeCPNPs) have been prepared for the first time by simple mixing of ferric chloride and sodium hexametaphosphate (SHAM) aqueous solutions at room temperature. It was found that such FeCPNPs possess peroxidase-like activity capable of catalyzing the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) by H₂O₂ turning the solution blue in color. Based on these findings, a simple, sensitive and selective colorimetric assay to detect H₂O₂ was developed, with the linear range and detection limit estimated to be from 1 μM to 50 μM (r = 0.997) and 0.4 μM, respectively. The application of this colorimetric assay to glucose detection both in buffer solution and diluted serum has also been demonstrated successfully. This glucose sensor exhibits excellent performance with a linear range from 2 μM to 20 μM (r = 0.985) and a detection limit of about 1 μM.