Ratiometric Fluorescent Sensor Based on Core–Shell Structural Silica Nanoparticle for H2O2 Detection

Hydrogen peroxide (H2O2) plays a very vital role in industrial and biological processes, but its high concentration may cause health hazards. Therefore, accurate detection of H2O2 is crucial for chemical and biological sensing applications. In this work, a ratiometric fluorescent probe was developed using a core–shell structural silica nanoparticle for the detection of H2O2. Firstly, a silica core structure with red fluorescence emission was constructed by encapsulating a Schiff base compound (SD). Afterwards, a mesoporous silica shell was fabricated, and the AIE featured fluorophore with a H2O2 response character was covalently linked on the surface of the mesoporous shell layer. As recognition sites on the shell, blue-emitting TB molecules specifically identified H2O2 through their phenylboronic acid ester group. The blue fluorescence of core–shell structural nanoprobes would be quenched in the presence of H2O2, while red fluorescence remained unchanged, ensuring the high sensitivity and specificity of the ratio sensing. This design has demonstrated significant potential for the reliable monitoring of hydrogen peroxide in biological and environmental applications.