Del Barrio Redondo, MelisaMarcos, Susana deCebolla, VicenteHeiland, JosefWilhelm, StefanHirsch, ThomasGalbán, Javier2024-01-152024-01-152014Del Barrio, Melisa, et al. «Enzyme-Induced Modulation of the Emission of Upconverting Nanoparticles: Towards a New Sensing Scheme for Glucose». Biosensors and Bioelectronics, vol. 59, septiembre de 2014, pp. 14-20. https://doi.org/10.1016/j.bios.2014.02.076.0956-566310.1016/j.bios.2014.02.076https://hdl.handle.net/20.500.14352/93057A new approach for the design of a fluorometric biosensor for continuous monitoring of glucose levels in biological samples based on near-infrared (NIR) excitation is described. The sensor combines the fluorescence of the enzyme glucose oxidase (GOx) chemically modified with a fluorescein derivative (FS) and the luminescent properties of upconverting luminescent nanoparticles (UCLNPs). Both, the chemically modified enzyme (GOx-FS) and the UCLNPs are immobilized in a poly(acrylamide) film as a physical support. The excitation of the UCLNPs with NIR light is of major advantage, since fluorescence background from the matrix is minimized. The upconverted luminescence is used to excite GOx-FS, which undergoes a change in the fluorescence intensity during the enzymatic reaction with glucose. The sensor comprises sufficient stability and covers the physiological range of glucose levels in blood. Furthermore, in a proof of principle experiment, the sensor system responds linearly to glucose concentrations in the range from 3.3 to 16.6. mM in flow injection analysis mode.engjournal articlehttps://doi.org/10.1016/j.bios.2014.02.076restricted access543Glucose biosensorUpconverting nanoparticlesNear-infrared excitationGlucose oxidaseQuímica analítica (Química)2301 Química Analítica