| 摘要 |
An improved biological probe is disclosed that employs a plurality of groups of modified single-stranded DNA attached to a single electrode. Using a plurality of such groups increases the inherent sensitivity of the probe by providing additional hybridization location sites and also serves to improve performance by diminishing steric hindrance caused by the crowding and tangling of the long single-stranded oligionucleotide molecules. The modification of the oligionucleotides involves the attachment of electron donor and acceptor moieties that alters the electrochemical properties of the hybridized molecules. The selected groups of modified oligionucleotides are complementary to unique characteristic sequences of the target DNA or RNA. A sample that containing oligionucleotides of a target biological agent is brought into contact with the probe and complementary portions of the molecules will hybridize with the oligionucleotides attached to the probe. When voltage is applied to the electrode, current will flow through the hybridized molecules with little resistance. Measurement of the current or changes in the current within the probe will indicate the presence of target DNA or RNA. |
