Visual detection and tracking of toxic mercury in biological cells using biocompatible mesoporous silica nanospheres

Abstract

A novel, cost-effective, eco-friendly, and straightforward approach is urgently required to assess the distribution, localization, and concentration of toxins in biological cells, as their accumulation poses significant health risks. Herein, we report innovative fabrication of biocompatible silica nanospheres for real-time tracking, visualization, quantification, and clinical diagnosis of Hg(II) poisoning in cells, employing ultra-sensitive and ultra-selective assays. The creation of a biocompatible yolk-like nanosphere with a highly accessible hollow interior cavity resulted in a distinctive porous structure, providing ultra-precise recognition of Hg(II) at trace levels. The low limits of detection (LOD) and quantification (LOQ) for fluorometric monitoring of Hg(II) ions were determined as 0.11 ppb and 0.33 ppb respectively. Simple, portable, and batch analyses were employed for the rapid and continuous visualization, quantification, and inhibition of ultra-trace Hg(II) concentrations (up to ppb) in HeLa cells, aiming to assess the suitability of the innovative nano- tracker hybrid. The results showed exceptional biocompatibility of the nano-tracker hybrid. The straightforward penetration and binding pathways of the nanospheres through the cell membrane were examined. Moreover, outstanding emission enhancement was observed in the intracellular area under biological conditions. The adorned nanotrackers could serve as valuable tools for visualizing and monitoring Hg(II) poisoning during in vitro assays for clinical diagnosis in HeLa cells.