Inhibition effect-involved colorimetric sensor array based on PtBi aerogel nanozymes for discrimination of antioxidants

Abstract

Nanozymes, as superior alternatives to natural enzymes, frequently employ the inhibition effect in turn-off sensors for analyte detection. However, limited attention has been paid to the inhibition mechanisms between analytes and nanozymes, limiting advancements in nanozyme-based sensing. Benefiting from the synergistic effects between three-dimensional network structure of aerogel and ligand effect triggered electronic regulation, Pt₁₀₀Bi₂ aerogel nanozymes (Pt₁₀₀Bi₂ ANs) exhibit superior peroxidase-like activity (293.48 U/mg). We found that antioxidants were able to inhibit the peroxidase-like activity of Pt₁₀₀Bi₂ ANs. The inhibition type (gallic acid as model) is reversible mixed-inhibition with the inhibition constants (K_i and K_i’) of 0.213 mM and 0.108 mM. The inhibition effect-involved colorimetric sensor arrays were developed to overcome the “lock-key” limitation of traditional sensors, enabling distinguish five antioxidants via principal component analysis, with detection limit below 2 μM. This work provides new perspective on the inhibition mechanisms of nanozymes and optimization strategies for high-performance nanozyme-based sensors.