Development of a selective prilocaine optical sensor based on molecularly imprinted film on CdTe quantum dots

Ali A. Ensafi, N. Kazemifard, B. Rezaei

Abstract

A sensitive optical sensor, using a molecularly imprinted film on CdTe quantum dots (CdTe QDs), is developed for the selective detection of prilocaine. At the first step of this work, water-soluble thioglycolic acid capped CdTe QDs (TGA capped-CdTe QDs) were prepared using refluxing method. At the next step, a thin film of silica was formed, by reverse microemulsion technique, on the surface of CdTe quantum dots. Finally, molecularly imprinted polymer embedded CdTe QDs were obtained. In this step, 3-aminopropyltriethoxysilane (APTS) and tetraethoxysilane (TEOS) were applied as a functional monomer and a cross linker, respectively. Different variables affecting the optical signal were optimized. Under optimal conditions, the dynamic range of the optical sensor was 5.5 to 260.0 nmol L^-1 prilocaine with a detection limit as low as 0.6 nmol L^-1. The relative standard deviations of 5.3% and 7.5% for 126 and 35 nmol L^–1 prilocaine (n = 3) were observed. The response of the optical sensor on common species in biological media was investigated. The results confirmed the good selectivity of the sensor for the measurement of prilocaine.

Keywords: Prilocaine; CdTe quantum dots; molecularly imprinted polymer; Optical sensor; Reverse microemulsion technique.