RESUMO
Ferrocene-modified DNA probes formed fully matched duplexes and bulge-containing ones with wild-type and insertion/deletion-type complements of clinical importance, respectively. Cyclic voltammetry measurements revealed that the bulge-containing duplexes showed an increased flexibility compared to the fully matched duplexes. The difference in the bending elasticity could be read out electrochemically by square wave voltammetry.
Assuntos
Sondas de DNA/química , DNA/genética , Eletroquímica/métodos , Compostos Ferrosos/química , Mutagênese Insercional , Deleção de Sequência , Sequência de Bases , Eletrodos , MetalocenosRESUMO
Cyclic voltammetry was performed at various scan rates for the duplexes from ferrocene/isoquinoline conjugate-connected DNA probes on gold electrodes. The relationship between the observed currents and the scan rates disclosed the enhanced bending elasticity of the mismatched duplexes compared with the fully matched duplexes. The difference of the dynamics was easily detected through the currents from the conjugate by adjusting the pulse potential frequency in square-wave voltammetry. By using the present strategy, we succeeded in accurately detecting various naturally occurring single-nucleotide polymorphisms.
Assuntos
Sondas de DNA/síntese química , Eletroquímica/métodos , Eletrodos , Compostos Ferrosos/síntese química , Isoquinolinas/síntese química , Polimorfismo de Nucleotídeo Único , Sondas de DNA/química , Sondas de DNA/genética , Compostos Ferrosos/química , Isoquinolinas/química , MetalocenosRESUMO
Establishing a reliable genotyping protocol is a critical matter in post-sequence genetics. In this article, we describe a highly sensitive electrochemical detection of complementary DNAs (up to 43-mer) based on hole transport with molecular-scale, "wire-like" DNA probes. The presence of a single-base mismatch in the DNA duplexes caused a dramatic decrease in the electrochemical response. We applied this method to detect all of the possible transition and transversion SNPs and achieved "on-off"-type discrimination of fully complementary DNAs from their SNPs. Furthermore, naturally occurring polymorphisms, "hot spots" from the p53 gene, could clearly be distinguished from wild type by using our methodology.
