Molecularly imprinted mesoporous silica embedded with carbon dots and semiconductor quantum dots as a ratiometric fluorescent sensor for diniconazole

Abstract

A dual-emission mesoporous structured molecularly imprinted sensor was designed for specific recognition and sensitive ratiometric detection of diniconazole ‏ (DNZ). In this probe, a carbon dot-doped silica core serves as a reference and provides a built-in correction for environmental effects. CdTe/CdS quantum dots (QDs) are encapsulated in the pores of the mesoporous silica and provide analytical signal. The fluorescence of CdTe/CdS QDs is selectively quenched in the presence of DNZ‏, accompanied by a visual green-to-blue color switch. The sensor has a linear response in the range of 20-160µgL^-1 with a detection limit of 6.4µgL^-1 and excellent recognition specificity for DNZ over its analogs. The applicability of the developed method for analysis of real samples was evaluated through the determination of DNZ in soil, river water and wastewater samples and satisfactory recoveries were obtained.

Keywords: C-dots; Diniconazole; Mesoporous silica; Molecularly imprinted polymer; Quantum dots; Ratiometric sensor.