Sensitive and Selective Detection of N,N-Dimethyltryptamine with Molecularly Imprinted Polymer Coupled with Electrogenerated Chemiluminescence

Abstract

One of the challenges in analytical chemistry is to develop a method that is not only sensitive but also selective for detection and quantification of a target analyte. Herein, we report a strategy that combines a molecularly imprinted polymer (MIP) as the selective element with electrogenerated chemiluminescence (ECL) as the sensitive analytical signal generator for detection of a hallucinogenic drug N,N-dimethyltryptamine (DMT). MIPs hold specific binding capability toward probed targets, and their molecular recognition behavior is similar to that of specific antibodies to antigens or probe single-strand DNAs to complemental target DNA sequencies. Additionally, MIPs are chemically stable, easily synthesized, and cost-effective. On the other hand, ECL has been regarded as one of the most sensitive analytical techniques for ultra-trace analyte determination. This is because ECL is a kind of spectroscopy initiated by electrochemistry without using any light source. For the present work, DMT specific MIPs were prepared by anodic electrodeposition of aminobenzoic acid as monomer mixed with DMT as template molecule on a glassy carbon electrode that had coated with a Ru(bpy)3 2+ trapped nafion film. ECL signals at the electrodes with DMT immobilized MIPs were acquired in a phosphate buffered solution upon the anodic potential scanning. A non-imprinted polymer (NIP) was also prepared in absence of template under similar conditions. The MIP-ECL sensor showed a wide dynamic range of 0.05 to 100 µM to DMT with an estimated detection limit of 0.05 µM. The reproducibility, stability, and selectivity of the sensor were also examined. Figure 1