Phase fluorometric glucose biosensor using oxygen as transducer and enzyme-doped xerogels

The development of a glucose biosensor based on co-immobilisation of oxygen (O₂) responsive luminophore and glucose oxidase (GOx) within nanoporous solgel-derived xerogels is described. The biosensor operates in the frequency domain and exploits the effect of glucose and O₂ consumption by GOx on the luminophore excited-state lifetime (i.e. phase angle). The biosensor consists of a modulated light emitting diode as the excitation source and a silicon photodiode as the detector. This sensing methodology establishes the viability for low-cost and accurate biosensors that operate at a low modulation frequency (tens of kHz). The biosensor is stable, reproducible, and provides an analytically reliable response from 0.5 to 15 mM glucose