Silica Nanoparticle-Enhanced Fluorescent Sensor Array for Heavy Metal Ions Detection in Colloid Solution

Abstract

Sensitivity and detection limit are two vital factors that affect fluorophores-based sensing and imaging system. However, it remains a challenge to improve the sensitivity and detection limit of fluorophores, largely due to their limited response and photophysical properties. In this study, we report for the first time, a novel approach to enhance the sensitivity and detection limit of probes using silica nanoparticles, also known as silica nanoparticles-enhanced fluorescence (SiEF). SiEF can drastically improve the fluorescence intensities and detection limit of fluorophores. A SiEF-improved fluorescent sensor array for rapid and sensitive identification of different heavy metal ions is achieved, and a 3D spatial dispersion graph is obtained based on the SiEF-improved fluorescent sensor array, which provides a lower concentration dependent pattern than fluorophores alone, allowing qualitative, quantitative, and sensitive detection of heavy metal ions. Furthermore, with UV lamp irradiation of the sensor–metal ion mixtures, the output signals enable direct visual of heavy metal ions with low concentration. Thus, the SiEF approach provides a simple and practical strategy for fluorescent probes to improve their sensitivity and detection limit in analytes sensing.