Simultaneous quantitative analysis of K+ and Tl+ in serum and drinking water based on UV–Vis spectra and chemometrics

The simultaneous detection of K + and Tl + can serve as a toxicological diagnostic tool for thallium poisoning. Colorimetric-reaction-based nanoprobes have emerged as promising sensors for the rapid and ultrasensitive detection of molecular species in simple systems. However, the development of viable screening tools for multicomponent analysis in complex systems remains challenging owing to interference from coexisting materials in the media. Herein, a simple chemical sensor array based on the peroxidase-like activity of gold nanoparticles modified with single-stranded DNA (AuNPs-ssDNA) and chemometrics was developed for the simultaneous detection of K + and Tl + in aqueous solutions and serum. The use of a K + adapter conferred high selectivity to the developed method. Optimized AuNPs-ssDNAs were used to construct a sensor array, which together with chemometrics provided fingerprints that can facilitate the simultaneous analysis of multiple components. The developed colorimetric reaction in combination with the chemometrics assay was directly used as a biosensor array, which exhibited detection limits of 107.33 nM for K + and 19.26 nM for Tl + . The developed method could potentially serve as a diagnostic technique for investigating thallium poisoning and toxicology.