Nature Communications
Pin Dong1, Kezheng Li1, Dave D. Rowe2, Ganapathy Senthil Murugan2, Thomas F. Krauss1 and Yue Wang1
- School of Physics Engineering and Technology, University of York, Heslington, York YO10 5DD, UK
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
Abstract
Therapeutic drug monitoring (TDM), involving the measurement of drug levels in patients’ body fluids, is an important procedure in clinical practice. However, the analysis technique currently used, i.e. liquid chromatography–tandem mass spectrometry (LC-MS/MS), is laboratory-based, so does not offer the short response time that is often required by clinicians. We suggest that techniques based on Fourier Transform Infrared Spectroscopy (FTIR) offer a promising alternative for TDM. FTIR is rapid, highly specific and can be miniaturised for near patient applications. The challenge is, however, that FTIR for TDM is limited by the strong mid-IR absorption of endogenous serum constitutes. Here, we address this issue and introduce a versatile approach for removing the background of serum lipids, proteins and small-water soluble substances. Using phenytoin, an antiepileptic drug as an example, we show that our approach enables FTIR to precisely quantify drug molecules in human serum at clinically relevant levels, providing an efficient analysis method for TDM. Our study opens the door to an untapped integrable point-of-care modality based on mid-IR spectrometry for TDM.