Yaling Yang

Herein, a novel bimetallic (Fe,Cu/His) nanozyme with high peroxidase (POD)-like activity for colorimetric assaying of glucose was designed. Assisted by glucose oxidase (GOx), glucose could be specifically converted into H₂O₂ for oxidizing chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) catalyzed by Fe,Cu/His to generate blue oxTMB with absorption at 654 nm. Specifically, Fe,Cu/His exhibits excellent POD-like activity due to ascorbic acid with reducing properties to ensure the formation of binary-valence metal pairs (Fe³⁺/Fe²⁺ and Cu²⁺/Cu⁺), thus enhancing electron transfer during the catalytic process. Based on the cascade reaction of GOx and the Fe,Cu/His nanozyme, a sensitive colorimetric assaying platform for glucose detection was constructed with a good linear range of 5–1000 µM and a calculated limit of detection of 1.44 µM. This proposed method was applied to assay glucose in tobacco samples sensitively and accurately.

Using S-, Se-, N-doped carbon dots, SERS-active gold nanoparticles were prepared. A sensitive sensor for 6-methyl nicotine in e-cigarettes was established via specific S-Au/Se-Au/N-Au interactions, with a detection limit of 0.13 μg L ⁻¹ .

Cu-g-C ₃ N ₄ was combined with AuNPs to act as support and co-catalyst, yielding a highly active and stable POD-mimicking nanozyme (Cu-g-C ₃ N ₄ /AuNP). With H ₂ O ₂ , it rapidly oxidized AT to fluorescent ox-AT, producing distinct SERS signal changes.