In this review we explore the advantages deriving from the use of either enzymes or binding proteins to develop non-consuming substrate fluorescence biosensors. We report on a novel approach to address the consumption of substrate by enzyme-based biosensors, namely the utilization of apo-enzymes as non-active forms of proteins, which through still able to bind the ligand yet cannot transform it into product. We also report recent studies in which fluorescence labelling of a naturally thermostable binding protein by a fluorescent probe allows a quantitative monitoring of glucose. Finally, we will illustrate a novel methodology based on the utilization of porous silicon chips that allows a nanotechnological approach to the realization of protein arrays for analyses of high medical and biochemical interest.
Keywords: Porous silicon, proteins, diabetes, fluorescence, biosensors