A NADH-dependent fiber-optic biosensor for ethanol determination with a UV-LED excitation system

A fluorometric fiber-optic biosensor for ethanol determination was constructed and tested. An ultraviolet light emitting diode (UV-LED) was used as a fluorescence excitation source for nicotinamide adenine dinucleotide (NADH). The use of a UV-LED conferred the advantages of low power consumptions and the potential for portable application. The biosensor consists of a UV-LED based portable excitation system (lambda = 340 nm), fiber optic spectrometer and an optical fiber probe with an alcohol dehydrogenase immobilized membrane. These instruments were connected using a Y-shaped optical fiber assembly. According to the experimental assessment, the power consumption was reduced to one percent of general UV light source. The measurement system was useful for 1.00-300 mu mol L-1 of NADH. EtOH measurement test was also carried out. The wide calibration range of the EtOH biosensor was 0.10-100.00 mmol L-1, with high selectivity versus other chemical substances. The biosensing system is simplified and miniaturized by use of LED in compare with previous methods. For this advantage, the biosensing system is expected to be used for point-of-care testing applications or daily health care tests. (C) 2009 Elsevier B.V. All rights reserved