Evangelia Vezouviou et al., have reported a near infrared holographic glucose sensor. Real-time glucose monitoring has been beneficial in reducing health complications associated with diabetes as well as a decrease in mortality. This report describes a novel holographic platform, fabricated via laser ablation on chitosan hydrogel with gold nanoparticles with a replaying in visible and near IR. The sensor responded with a 12nm and 7nm shift in waveleng that glucose concentrations in the 0.70 mM range and in the visible and near IR, respectively, at pH 7.4 and an ionic strength of 154 mM. The sensor did not respond to potential interferences found in the interstitial fluid, such as fructose, vitamin C and lactate, at the irrespective normal concentrations and was stable to fluctuations in temperature, pH and ionic strength. The characteristics of this sensor suggest that it may be applicable for use as an implanted device for the real time monitoring of glucose concentrations in the interstitial fluid using near IR as the interrogating medium.
Holographic fabrication. A photosensitive emulsion (1) coated on a glass slide (2) is placed inside a tray with a 7° spacer (3) and facing towards a reflecting mirror (4).Upon exposure to the laser irradiation (5), the gold nanoparticle grains are arranged in fringes (6) align in parallel to the surface of the polymer, and are separated by half the distance of the wavelength they were exposed to. The diagram is not to scale.
Evangelia Vezouviou, Christopher R. Lowe – 2015 – Biosensors and Bioelectronics 68 ,371–381.
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