Open AccessMetal‐free phthalimide‐labeled peptide nucleic acids for electrochemical biosensing applications
Author(s) -
Magni Mirko,
Dall'Angelo Sergio,
Baldoli Clara,
Licandro Emanuela,
Falciola Luigi,
Mussini Patrizia R.
Publication year - 2022
Publication title -
electrochemical science advances
Language(s) - English
Resource type - Journals
ISSN - 2698-5977
DOI - 10.1002/elsa.202100164
Subject(s) - nucleic acid , combinatorial chemistry , phthalimide , chemistry , rna , peptide nucleic acid , dna , biosensor , nucleobase , peptide , nucleic acid analogue , potentiometric titration , nucleic acid thermodynamics , biochemistry , organic chemistry , ion , gene
Peptide nucleic acids (PNAs) are neutral mimics of natural DNA and RNA biopolymers that have caught the attention of researchers working on the identification of specific sequences of nucleobases in DNA/RNA strands. For this purpose, specific analytical protocols need to be developed to optimize the nucleic acid recognition ability of PNAs, exploiting both the high intrinsic affinity of PNA/DNA(RNA) couples as well as suitable markers, either linked to the PNA backbone or properly interacting with it in the working medium. In this context, the paper reports on phthalimide and 4‐nitrophthalimide as two cheap, metal‐free electroactive markers covalently bound to the pseudo‐peptide backbone of a PNA decamer. After a preliminary characterization of the markers, as such and in PNA conjugates, attention has been moved toward the optimization of the detectability of the labeled PNA decamers in aqueous solutions. Exploiting the potentiometric stripping analysis on hanging mercury drop electrode it has been possible to reach satisfactory detection limits of ca. 10 nM avoiding the use of expensive transition metal complexes as labels and/or of co‐reagents.