Publications

Protocol for Therapeutic Drug Monitoring Within the Clinical Range Using Mid-infrared Spectroscopy

Therapeutic drug monitoring (TDM), which involves measuring 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 miniaturized for near-patient applications. The challenge, however, is that FTIR for TDM is limited by the strong mid-IR absorption of endogenous serum constituents. 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 (10 μg/mL), providing an efficient analysis method for TDM. Beyond mid-IR spectroscopy, our study is applicable to other drug sensing techniques that suffer from the large background of serum samples.

Suspended germanium waveguides with subwavelength-grating metamaterial cladding for the mid-infrared band

In recent years, sensing and communication applications have fueled important developments of group-IV photonics in the mid-infrared band.

Subwavelength-grating metamaterial integrated devices for the near- and mid-infrared wavelengths

The subwavelength patterning of planar structures is now widely used in silicon photonics, enabling the synthesis of metamaterials with engineered optical properties, including refractive index, dispersion, and anisotropy.

Suspended germanium waveguides with metamaterial lateral cladding for mid-infrared integrated photonics

We demonstrate a suspended germanium waveguide platform with a propagation loss of 5.3 dB/cm at a wavelength of 7.7 µm, with potential applications in free-space optical communications and absorption sensing.

Group IV mid-infrared photonics for communications and sensing

We review our recent results on modulators and detectors for the 2μm range, which may become very relevant for future communications, and on the development of mid-IR broadband devices for sensing applications.

Prediction of Neonatal Respiratory Distress Biomarker Concentration by Application of Machine Learning to Mid-Infrared Spectra

The authors of this study developed the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) combined with machine learning as a point-of-care (POC) diagnostic platform.

Metasurface-enhanced mid-infrared spectroscopy in the liquid phase

Vibrational spectroscopy is an important tool in chemical and biological analysis. A key issue when applying vibrational spectroscopy to dilute liquid samples...

Detection of paracetamol binding to albumin in blood serum using 2D-IR spectroscopy

Binding of drugs to blood serum proteins can influence both therapeutic efficacy and toxicity.

The Effect of Haematocrit on Measurement of the Mid-Infrared Refractive Index of Plasma in Whole Blood

Recent advances suggest that miniaturised mid-infrared (MIR) devices could replace more time-consuming, laboratory-based techniques for clinical diagnostics.

Mid-infrared silicon-on-insulator waveguides with single-mode propagation over an octave of frequency

Increasing the working optical bandwidth of a photonic circuit is important for many applications, in particular chemical sensing at mid-infrared wavelengths.