Point-of-Care Therapeutic Drug Monitoring Kit using Nanoimprint Lithography-Based Flexible Two-Dimensional Photonic Crystals

Yamada, Kenji ;   Jeong, Hieyong ;   Kido, Michiko ;   Ohno, Yuko ;   Yoshimoto, Kayo ;   Yagi, Masakazu

It is expected that Therapeutic Drug Monitoring (TDM) is used in clinical use. Especially, point-of-care TDM needs a simple, rapid, low-cost, minimally-invasive drug measurement tool. We have developed the point-of-care therapeutic drug monitoring kit based on Raman Spectroscopy of tear fluid. We have used the paper based substrate, because paper is very safe tear collection tool. Though we were able to detect 1mM Phenobarbital concentration spectra, it is very low for the effectiveness of SERS using paper based substrate with drug monitoring. It is able to be considered a cause that the lattice of gold nanorods on a paper substrate are not suitable for SERS effect. To perform more precise drug concentration detection, it is necessary to enhance the SERS effect is optimally positioned nanorods. In this study, we were examined an optimal lattice based on nanoimprint lithography using cyclo-olefin polymer to improve the sensitivity for measuring drug concentration in tear fluid. This is photonics crystal which is one of the nanophotonics based device was fabricated. Target is Sodium Phenobarbital which is an anticonvulsant agent. We show the effectiveness of Surface Enhanced Raman Spectroscopy of tear fluid with soft substrate for point-of-care therapeutic drug monitoring. For use in clinical practice, we challenge the further improvement of the sensitivity to drug solution down to 0.01mM for detecting a small amount of drug secreted in tear fluids.