Feasibility study of paper-based surface enhanced Raman spectroscopy of tear fluids for onsite therapeutic drug monitoring

This paper discuss drug concentration measurement based on Raman spectroscopy of tear fluids with paper substrates for on-site therapeutic drug monitoring (TDM). We focus on tear fluids as alternative specimens to blood for minimally-invasive TDM. By using paper substrates, specimen collection and measurement based on surface enhanced Raman spectroscopy will be performed easily and inexpensively. In experiment, we fabricated paper-based substrate for surface enhanced Raman spectroscopy (SERS) of tear fluids and evaluated its surface. Scanning electron microscope images of them showed that gold nano-rods were adsorbed on the surface uniformly. This result implies that analysis of tear fluids with paper substrates would be realized with high sensitivity by SERS.

I. Introduction

Therapeutic drug monitoring (TDM) is used to monitor and maintain the drug level within the concentration range in which a drug exerts its clinical effect with minimal adverse effect [1]. The drug concentration value provided by TDM is a good index in assessment of pharmacological effect and patient's medication compliance. Furthermore, it helps clinicians to adjust the dosage according to the characteristics of individual patient, and it optimizes the pharmacotherapy. Point-of-care testing (POCT) of drug concentration would realize prompt decisions in pharmacotherapeutic field and improves the quality of medical care.