Multienzyme mimetic activities of holey CuPd@H–C₃N₄ for visual colorimetric and ultrasensitive fluorometric discriminative detection of glutathione and glucose in physiological fluids

Nanozymes with multiple activities have drawn immense interest owing to their great prospect in biochemical analysis. Fabricating nanomaterials-based artificial enzymes for multiple-enzyme mimetic activity is a significant challenge. This paper reports a sensitive biosensing platform to mimic the peroxidase, oxidase, and catalase-like activity by bimetallic CuPd embedded holey carbon nitride (CuPd@H–C₃N₄). Owing to the combination of porous H–C₃N₄ and bimetallic CuPd nanoparticles, the CuPd@H–C₃N₄ exhibited a large specific surface area, extremely high mobility and catalytic activity of electrons, resulting in remarkable triple-enzyme mimetic activity. Owing to the excellent oxidase/peroxidase-like activities of CuPd@H–C₃N₄, a visual colorimetric and ultrasensitive fluorometric biosensing platform was established for the discriminatory detection of glutathione (linear range: 2–40 μM) and glucose (linear range: 0.1–40 μM) in physiological fluids, respectively. The fluorescence detection system showed ultrahigh sensitivity toward H₂O₂, with a linear range of 30–1500 nM. In addition, a one-step glucose detection strategy was proposed to replace the traditional, complicated two-step detection method, which simplifies the operation steps and improves the detection efficiency. The assay presented in this paper offers an effective multiple-enzymes mimicking detection platform that broaden its promising applications in biomedicine analysis and monitoring.