Colorimetric Sensor for Kanamycin Based on Peroxidase-Like Activity of Cu@Sch-HNT

This study demonstrates the synthesis of a Cu@Sch-HNT nanocomposite via an oil-bath-assisted approach, exhibiting enhanced peroxidase-mimetic activity. Comprehensive characterization employing electron paramagnetic resonance (EPR) spectroscopy and radical scavenging assays established <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{\bullet }$ </tex-math></inline-formula><inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\mathrm {O}}_{{2}}^{-}$ </tex-math></inline-formula> radicals as the predominant reactive species governing the catalytic mechanism. Optimal enzymatic activity was observed at physiological temperature, indicative of favorable biocompatibility. Capitalizing on these catalytic properties, a rapid colorimetric sensing platform was engineered for kanamycin detection. Quantitative analysis revealed a significant linear correlation between kanamycin concentration and absorbance at 652 nm, with detection limit determination conducted according to standard signal-to-noise ratio criteria. This methodology affords three principal advantages as follows: 1) visual analyte recognition through distinct chromogenic transitions; 2) high sensitivity confirmed by systematic detection limit assessment; and 3) practical utility validated through recovery analyses in complex matrices. The platform demonstrates significant potential for environmental surveillance and biosensing applications, particularly in resource-constrained environments.