A novel photometric glucose biosensor based on decolorizing of silver nanoparticles

A novel glucose biosensor based on chromophore (silver nanoparticles) decolorizing for the photometric determination of glucose was developed. Silver nanoparticles are directly synthesized in the sol–gel matrix by a one-step method based on the reduction of the inorganic precursor AgNO3 and were used for the preparation, characterization and calibration of a highly sensitive and cost-effective localized surface plasmon resonance-based glucose biosensor. In the presence of glucose oxidase (GOx) and due to the enzyme–substrate (glucose) reaction, H2O2 was produced and silver nanoparticles in the sol–gel glass have the ability for the decomposition of hydrogen peroxide. Due to the degradation of silver nanoparticles a remarkable change in the localized surface plasmon resonance absorbance strength could be observed which have been monitored as a suitable signal for determination of substrate concentration. Beer's law is obeyed in the range from 50 to 800 mg/L glucose and the limit of detection is 23 mg/L. The proposed optical biosensor has been successfully applied to the determination of glucose in various real samples.

► A simplified glucose biosensor based on AgNPs decolorizing has been developed.
► SPR of AgNPs is a sensitive analytical signal for constructing glucose biosensor.
► Sol–gel as the immobilization matrix for constructing of glucose biosensor was used.