Sequence-specific detection of short-length DNA via template-dependent surface-hybridization events.

Short-length DNA and RNA, such as mature small RNA, which contains only 17-25 nucleotides, are always a problem in hybridization-based detection assays. In this paper, we report a proof-of-concept for a new short-length DNA detection technology which encompasses a design strategy whereby capture and reporter probes that do not hybridize to each other at 20 degrees C can be made to anneal to each other in the presence of a template via the formation of a stable three-component complex. The thermodynamics of this magnetic bead-based DNA biosensor was then investigated in detail by monitoring chemiluminescence (CL) changes in the absence and presence of targets over a temperature profile. The data show that this new biosensor offers the possibility of highly selective and sensitive detection of the short-length target DNA. In view of these advantages, this template-dependent surface-hybridization assay, as a new CL strategy, might create a universal technology for developing simple biosensors in sensitive and selective detection of short-length DNA and RNA.