Electrostatic enzyme biosensor

Abstract

The device described herein is an enzyme-based biosensor for detecting and/or quantifying molecules of interest. The biosensor relies on the following properties shared by all enzymes: (1) that enzymes are highly specific molecules designed to bind with only one analyte type or one class of analyte molecules; (2) that enzymes contain charges; (3) that enzymes undergo significant spacial fluctuation during periods of interaction with substrates; and (4) that these spacial fluctuations cause the charged moieties on the enzyme to move and thus generate a measurable electrostatic potential (voltage) in both the enzyme and support layers. The instant device determines analyte presence/concentration through measurement of changes in voltage or current in a conducting or semiconducting support material as a result of changes in the position of immobilized charged enzyme molecules during their interaction with analyte. More particularly, the instant device immobilizes enzyme molecules sufficiently close to a conducting or semiconducting layer to insure that any alteration in the position of charged groups of the enzyme during interaction with analyte will cause the generation of a voltage in the base layer. When the enzymes encounter the targeted analyte the enzymes move, thus causing the enzyme charges to move. The movement of charges, in turn, changes the electrostatic field around the enzymes and results in a corresponding generation of a dipole (as measured in a generated voltage) in the conducting or semiconducting base layer. The presence and quantity of generated voltage is used to signal the presence and quantity of analyte.