Ultrafast and sensitive colorimetric detection of ascorbic acid with Pd-Pt core-shell nanostructure as peroxidase mimic

Abstract

In recent years, nanostructures with peroxidase-like properties (i.e. peroxidase mimics) have attracted special interest due to their low costs, decent stabilities, and high catalytic activities. Herein, we demonstrate the use of Pd-Pt core-shell nanocubes (NCs) as efficient peroxidase mimics to achieve rapid and sensitive colorimetric detection of ascorbic acid (AA, which is commonly known as vitamin C). The color signal generated by the Pd-Pt NCs catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H2O2 is quenched in presence of AA based on its antioxidant property. This colorimetric method attains a detection limit of 0.40 μM and a linear range of 0–15 μM, with good linearity. To the best of our knowledge, the method reported in this work presents the fastest AA detection among all the other reported colorimetric methods, with only a 3-min reaction time. Furthermore, this method features a simple procedure, cost-effectiveness, room temperature conditions and good stability.