Molecularly imprinted polymer coated quantum dots for fluorescence sensing of acetaminophen

Abstract

A molecularly imprinted coating with acetaminophen (AC) as template molecule was grafted onto L-cys-CdSe/ZnS quantum dots (QDs) using 3-aminopropyltriethoxysilane as the functional monomer and tetraethyl orthosilicate as the cross-linker via an adapted Stöber method, in order to develop a selective and sensitive fluorescence sensor for the determination of AC in water samples. The resulting MIP@QDs were characterized by Fourier-transform infrared spectroscopy, high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis and fluorescence spectrophotometry which confirmed the polymer coating. The fluorescence quenching of the sensor provided good linearity over the AC concentration range of 1.0–300 nmol L−1 with a detection limit of 0.34 nmol L−1 and the sensor showed good photostability over 5 days. The recoveries of AC in water samples at various spiking levels varied from 95% to 114%.