Glucose sensing by waveguide-based absorption spectroscopy on a silicon chip

• Published in: Biomedical optics express 2014-05, Vol.5 (5), p.1636-1648
• Main Authors: Ryckeboer, E, Bockstaele, R, Vanslembrouck, M, Baets, R
• Format: Article
• Language: English
• Subjects: Biosensors and Molecular Diagnostics
• ISSN: 2156-7085; 2156-7085
• DOI: 10.1364/BOE.5.001636

In this work, we demonstrate in vitro detection of glucose by means of a lab-on-chip absorption spectroscopy approach. This optical method allows label-free and specific detection of glucose. We show glucose detection in aqueous glucose solutions in the clinically relevant concentration range with a silicon-based optofluidic chip. The sample interface is a spiral-shaped rib waveguide integrated on a silicon-on-insulator (SOI) photonic chip. This SOI chip is combined with micro-fluidics in poly(dimethylsiloxane) (PDMS). We apply aqueous glucose solutions with different concentrations and monitor continuously how the transmission spectrum changes due to glucose. Based on these measurements, we derived a linear regression model, to relate the measured glucose spectra with concentration with an error-of-fitting of only 1.14 mM. This paper explains the challenges involved and discusses the optimal configuration for on-chip evanescent absorption spectroscopy. In addition, the prospects for using this sensor for glucose detection in complex physiological media (e.g. serum) is briefly discussed.