Metal‐free phthalimide‐labeled peptide nucleic acids for electrochemical biosensing applications

Peptide nucleic acids (PNAs) are neutral mimics of natural DNA and RNA biopolymers that have caught the attention researchers working on identification specific sequences nucleobases in DNA/RNA strands. For this purpose, analytical protocols need to be developed optimize acid recognition ability PNAs, exploiting both high intrinsic affinity PNA/DNA(RNA) couples as well suitable markers, either linked PNA backbone or properly interacting with it medium. In context, paper reports phthalimide 4-nitrophthalimide two cheap, metal-free electroactive markers covalently bound pseudo-peptide a decamer. After preliminary characterization such conjugates, has been moved toward optimization detectability labeled decamers aqueous solutions. Exploiting potentiometric stripping analysis hanging mercury drop electrode possible reach satisfactory detection limits ca. 10 nM avoiding use expensive transition metal complexes labels and/or co-reagents.