Thin Film Sensor for Specific DNA Sequences

A chemical sensor has been discovered which can be made to sensitively detect enzyme activity and aantibody reactions. It consists of an ultrathin (25 Angstroms) layer of platinum on an insulating sumeasure dielectric constant and other properties within molecular-scale distances of the surface. Wesensor be adapted to measure nucleic acid hybridization. Short, 20-nucleotide probes will be bound ttheir 3'-ends. Complementary strands will be hybridized with the probes, and the effect on the impedsensor will be observed. The double-stranded form will differ greatly in shape, electrostatic chargeall of which should affect the response of the thin-film sensor. Such a sensor may be useful as a rediagnostic tool for early HIV infection, genetic diseases, pathogen identification, and forensic pur