Detection of point mutation in the p53 gene using a peptide nucleic acid biosensor

A 17-mer peptide nucleic acid (PNA) is used as the recognition layer of an electrochemical biosensor for detecting a specific mutation in the p53 gene. The performance of the PNA-derived biosensor is compared with that of its DNA counterpart. The significantly higher specificity of the PNA probe greatly improves the detection of a single point mutation, found in many types of cancer. Factors influencing the surface immobilization of the PNA probe, its hybridization to the p53 target sequence, and the chronopotentiometric detection step, are explored and optimized. This and similar developments hold promise for the diagnosis and management of cancer.