Universal Electrochemical Probe for Genotyping

DNA analysis is a fundamental topic of research leading to many studies related to the detection of disease-causing microbes, gene variations causing genetic disorders, DNA mapping, and evolutionary links between ancient and modern remains. This study uses stem-loop folded DNA (SLF-DNA) probe immobilized on the surface of an electrode as a part of tri-component sensor for detection of specific DNA. The advantages over traditional methods such as Southern and Northern Blots, or PCR amplification include the possibility to detect low quantities of unlabeled target analyte, high specificity of nucleic acid recognition and possibility to use the same immobilized DNA probe for detection of many different sequences.

In our approach hairpin shaped oligonucleotide (SLF-DNA) is immobilized onto a gold electrode and the signal of specific tag is measured. Importantly, immobilized SLF-DNA does not directly hybridize with the target analyte, but via the two adaptor strands. This design allows application of the same electrode in the same immobilized adaptor strand to be used for the detection of almost any target, relatively inexpensive adaptor should be changes to recognize a new DNA/RNA analyte. These electrochemical biosensors are simple to use, low cost, low power, portable with fast response times, and high specificity and sensitivity.