Highly luminescent tetra(biphenyl-4-yl)ethene-grafted molecularly imprinted mesoporous silica nanoparticles for fluorescent sensing of diethylstilbestrol

摘要

A molecularly imprinted mesoporous silica-based fluorescent sensor was prepared using a tetraphenylethene derivative (TBPE) as a signal transducer. Diethylstilbestrol (DES) was chosen as a target molecule and was connected to two triethoxysilane groups via thermally reversible urethane bonds. DES imprinted cavities with two-point binding sites were formed between the pores of the mesoporous silica by the sol-gel reaction and subsequent removal of DES. TBPE was selectively introduced to the pore surface. TBPE-grafted, DES imprinted mesoporous silica nanoparticle (TBPE-D1MSNP) showed a specific binding ability for the target template. The degree of fluorescence quenching of TBPE-DIMSNP was proportional to the concentration of DES. The sensitivity and selectivity of TBPE-DIMSNP were estimated by the Stern-Volmer equation. TBPE-DIMSNP displayed a much larger Stern-Volmer quenching constant for DES than for DES analogs with a high molecular imprinting factor. TBPE-DIMSNP also exhibited a great recovery of its initial fluorescence intensity even after several extraction and rebinding cycles.