Trace detection of tetrahydrocannabinol (THC) with a SERS-based capillary platform prepared by the in situ microwave synthesis of AgNPs

•An ultra-sensitive and highly reproducible novel SERS-based capillary platform.•Glass capillaries were coated with Ag nanoparticles by utilizing microwave-assisted synthesis in a batch fabrication process.•A high point-to-point and batch-to-batch SERS reproducibility.•1 nM of tetrahydrocannabinol (THC) is detected.

In the present study, an ultra-sensitive and highly reproducible novel SERS-based capillary platform was developed and utilized for the trace detection of tetrahydrocannabinol (THC). The approach combines the advantages of microwave-assisted nanoparticle synthesis, plasmonics and capillary forces. By employing a microwave-assisted preparation method, glass capillaries were reproducibly coated with silver nanoparticles in a batch fabrication process that required a processing time of 3 min without needing to use any pre-surface modifications or add surfactants. The coated capillaries exhibited an excellent SERS activity with a high reproducibility and enabled the detection of low concentrations of target molecules. At the same time, only a small amount of analyte and a short and simple incubation process was required. The developed platform was applied to the spectroscopic characterization of tetrahydrocannabinol (THC) and its identification at concentration levels down to 1 nM. Thus, a highly efficient detection system for practical applications, e.g., in drug monitoring/detection, is introduced, which can be fabricated at low cost by using microwave-assisted batch synthesis techniques.

Graphical abstractIn the present study, an ultra-sensitive and highly reproducible novel SERS-based capillary platform was developed. By utilizing microwave-assisted synthesis, glass capillaries were coated with silver nanoparticles in a batch fabrication process with a 3 minute processing time. The capillary-based platform exhibits a high point-to-point and batch-to-batch SERS reproducibility. Finally, the platform was applied to the spectroscopic characterization of tetrahydrocannabinol (THC) and its identification at concentration levels down to 1 nM.Download high-res image (263KB)Download full-size image