Glucose sensing in human epidermis using mid-infrared photoacoustic detection |
| |
Authors: | Kottmann Jonas Rey Julien M Luginbühl Joachim Reichmann Ernst Sigrist Markus W |
| |
Affiliation: | 1ETH Zurich, Institute for Quantum Electronics, Schafmattstrasse 16, 8093 Zurich, Switzerland;2University Children’s Hospital Zurich, Tissue Biology Research Unit, August Forel Strasse 7, 8008 Zurich, Switzerland |
| |
Abstract: | No reliable non-invasive glucose monitoring devices are currently available. We implemented a mid-infrared (MIR) photoacoustic (PA) setup to track glucose in vitro in deep epidermal layers, which represents a significant step towards non-invasive in vivo glucose measurements using MIR light. An external-cavity quantum-cascade laser (1010-1095 cm(-1)) and a PA cell of only 78 mm(3) volume were employed to monitor glucose in epidermal skin. Skin samples are characterized by a high water content. Such samples investigated with an open-ended PA cell lead to varying conditions in the PA chamber (i.e., change of light absorption or relative humidity) and cause unstable signals. To circumvent variations in relative humidity and possible water condensation, the PA chamber was constantly ventilated by a 10 sccm N(2) flow. By bringing the epidermal skin samples in contact with aqueous glucose solutions with different concentrations (i.e., 0.1-10 g/dl), the glucose concentration in the skin sample was varied through passive diffusion. The achieved detection limit for glucose in epidermal skin is 100 mg/dl (SNR=1). Although this lies within the human physiological range (30-500 mg/dl) further improvements are necessary to non-invasively monitor glucose levels of diabetes patients. Furthermore spectra of epidermal tissue with and without glucose content have been recorded with the tunable quantum-cascade laser, indicating that epidermal constituents do not impair glucose detection. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|