Molecularly Imprinted Fluorescent Sensors Based on Nitrogen-Doped CDs for Highly Selective Detection of Aspirin

Abstract

In this paper, we prepared a fluorescent sensor based on carbon quantum dots (CDs) and molecularly imprinted technology (MIT) that was successfully synthesized and applied to the detection of aspirin (Asp) residues in biological and pharmaceutical samples. The molecularly imprinted fluorescence sensor had the high sensitivity of quantum dots and the high selectivity of molecularly imprinted polymers (MIPs). Nitrogen-doped carbon quantum dots (N-CDs) with high fluorescence intensity were prepared and then was coated with silicon by the reverse microemulsion method. Finally, 3-aminopropyltriethoxysilane (APTES) was used as the functional monomer and Asp as the template molecule, molecularly imprinted layers were formed around the N-CDs. Under the best experimental conditions, the detection limit of the sensor was 0.198[Formula: see text]mg[Formula: see text]L[Formula: see text]. Between 0.9–9.0[Formula: see text]mg[Formula: see text]L[Formula: see text], this fluorescence sensor had a good linear relationship with the concentration of Asp. To test the practicability of the sensor, we used this fluorescent sensor to detect Asp in human urine and saliva. Satisfied recovery rate between 101.1–105.1% and 102.1–106.0% were obtained, respectively.