Preparation and entrapment of fluorescently labeled proteins for the development of reagentless optical biosensors

A new class of reagentless optical biosensors are emerging based on the use of engineered proteins that are site-selectively labelled with a fluorescent reporter group. Such sensors can operate either by direct interaction of the analyte with the bound probe, or by generating a fluorescence response to an analyte induced conformational change in the protein. In this review, the preparation, characterization and use of fluorescently labelled proteins for the development of reagentless optical biosensors is described. Recent work involving the rational design of fluorescent protein biosensors, and efforts at characterizing the origins of responses from these systems is highlighted. An overview of the recent and potential future trends in this area is also given. Finally, methods of immobilizing such biomolecules for the development of reuseable sensors are described.