Detection of theophylline using molecularly imprinted polymers based on thioglycolic acid-modified CdTe quantum dots
Maryam Zakery, Ali A. Ensaf1 · Behzad Rezaei
Journal of the Iranian Chemical Society (2020) 17:601–608, https://link.springer.com/article/10.1007/s13738-019-01798-w
Abstract Molecularly imprinted polymers (MIPs) and quantum dots (QDs) have been widely employed to fabricate highly sensitive and selective sensor. Here, we developed a fuorescence nanosensor based on thioglycolic acid-modifed CdTe QDs that is coated with molecularly imprinted polymers for the specifc detection of theophylline (THP). Initially, water-soluble thioglycolic acid-modifed CdTe QDs were synthesized by refuxing method. Then, MIPs-coated QDs (MIPs-QDs) composite was produced by sol–gel process using THP as a template. Therefore, the selectivity of the molecular imprinting technique and advantages of QDs were combined. The prepared QDs and the MIPs-QDs were characterized using X-ray difraction technique, transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectroscopy, and fuorescence spectrometry. Finally, this sensing system was successfully used to detect THP in human plasma samples with recoveries of 90% to 108%. A very good linear relationship was observed between the decreasing in the fuorescence intensity of MIPsQDs and increasing the THP concentration within concentration range of 0.14–3.05 µmol L−1, with a correlation coefcient of 0.9992 and detection limit of 0.07 µmol L−1.
Keywords Theophylline · Molecularly imprinted polymers · Thioglycolic acid-modifed CdTe QDs