Electronic sensors that are able to detect and measure the presence of biomolecules such as sugars or DNA segments. Currently created by:
- (a) Fusing organic matter (e.g., enzymes, antibodies, receptors, or nucleic acids) to tiny electrodes; yielding devices that convert natural chemical reactions into electric current to measure blood levels of certain chemicals (e.g., glucose or insulin), control functions in an artificial organ, monitor some industrial processes, act as a robot’s “nose,” etc.
- (b) Fusing organic matter (e.g., segment of DNA, antibody, enzyme, etc.) onto the surfaces of etched silicon wafers; yielding devices that convert supramolecular interactions [e.g., nucleotide hybridization, enzyme-substrate binding, lectin-carbohydrate (sugar) interactions, antibody-antigen binding, host-guest complexation, etc.] into electric current via a charge-coupled device (CCD) detector that measures the shift in interference pattern caused by change in refractive index that results when (sensed) molecule tightly binds to the fused organic matter. For such an etched-silicon-wafer biosensor, the nucleotide hybridization (binding) enables the detection of femtomolar (10-‘5 mole or 0.000000000000001) concentrations of DNA. If the (sensed) DNA segment is not complementary to the fused DNA segment, there is no significant change in the interference pattern.
A major future goal is to build future generations of biosensors directly into computer chips. (Researchers have discovered that proteins can replace certain metals in semiconductors.) This would enable low-cost mass production via processes similar to those now used for existing semiconductor chips, with circuits built right into the sensor to process data picked up by the biological matter on the chip.