Interfacially Super-Assembled Benzimidazole Derivative-Based Mesoporous Silica Nanoprobe for Sensitive Copper (II) Detection and Biosensing in Living Cells

Mesoporous silica nanoparticles (MSNs) functionalized with benzimidazole-derived fluorescent molecules (DHBM) are fabricated via a feasible interfacial superassembly strategy for the highly sensitive and selective detection of Cu2+. DHBM-MSN exhibits an obvious quenching effect on Cu2+ in aqueous solutions, and the detection limit can be as low as 7.69x10(-8) M. The DHBM-MSN solid-state sensor has good recyclability, and the silica framework can simultaneously improve the photostability of DHBM. Two mesoporous silica nanoparticles with different morphologies were specially designed to verify that nanocarriers with different morphologies do not affect the specific detectionability. The detection mechanism of the fluorescent probe was systematically elucidated by combining experimental results and density function theory calculations. Moreover, the detection system was successfully applied to detect Cu2+ in bovine serum, juice, and live cells. These results indicate that the DHBM-MSN fluorescent sensor holds great potential in practical and biomedical applications.