Establishing a reliable genotyping protocol is a critical matter in postsequence 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.electrochemistry ͉ hole transport ͉ ferrocene ͉ gold electrode

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.

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Get ready for take off: A planar‐chiral derivative of 4‐pyrrolidinopyridine (1) mediates the title transformation (see scheme) in a convergent manner with good enantioselectivity, thus giving the first catalytic asymmetric synthesis of aza‐β‐lactams.