Sol–gel encapsulated glucose oxidase arrays based on a pH sensitive fluorescent dye

Optical glucose oxidase (GOx) arrays based on pH sensitive fluorescent dye (2-(4-tolyl)-4-[4-(1,4,7,10-tetraoxa-13-azacyclopentadecyl)benzylidene]-5-oxazolone) (CPO) has been constructed. The arrays were prepared by spotting of CPO and GOx together with tetraethoxysilane (TEOS)/Chitosan (CHIT) mixture via a microarrayer. After optimization studies, analytical characterization of enzyme arrays were carried out. The fluorescence intensity of the system was linearly correlated to glucose concentration in the range of 1.0–30.0 mM (in potassium phosphate buffer; 2.5 mM at pH 7.0). Furthermore, the developed arrays were used to analyze glucose in some beverages and HPLC was used as a reference method for independent glucose analysis.