An oxidase-like nanozyme-based sensor array for the specific detection and discrimination of catechins†

In this study, a nanozyme-based sensor array was developed to achieve the identification and discrimination of three catechins (catechin, epicatechin, and epigallocatechin). The Fc@ZIF-67 NC nanozyme was synthesized with oxidase-like activity through the high-temperature carbonization of ferrocene-encapsulated ZIF-67. Two Fc@ZIF-67 NC-involved oxidase-like reactions were designed to generate three detectable signals (including two colorimetric signals and one fluorescent signal), which constituted the fingerprints of the analytes. By combining with linear discriminant analysis (LDA), different kinds and concentrations of catechins can be discriminated with this sensor array. Besides, the sensor array was proved feasible in the identification of catechins in real samples. This method provides a promising methodology for the discrimination and identification of natural products in food.