Fiber optic glucose sensor based on bionanofilms

In this paper a glucose fiber optic biosensor based on electrostatic self-assembly adsorption technique is proposed. Up to 35 bilayers biofilm was achieved from alternate deposition of enzyme glucose dehydrogenase and polyelectrolytes polyethyleneimine and poly(sodium 4-styrenesulfonate). The layer thickness was characterized using an in situ optical near infrared interferometry method, which showed formation of nanoscale multilayer structure as a function of alternate adsorption cycles. Experiments showed highly efficient adsorption. The catalytic effect of the multilayer film on the reduction of nicotinamide adenine dinucleotide was studied utilizing ultraviolet fiber optic spectroscopy. The performance of this nanobiofilm onto both the cleaved end of an optical fiber pigtail and a tapered optical fiber structure were compared. As a result enzymes kept their activities after immobilization; the biosensor showed high sensitivity and stability during storage.