Aptamers, nucleic acid molecules that fold into particular three-dimensional constructions, have been extensively used within the biosensing subject to perform delicate and particular monitoring of a variety of biomarkers. Peptide nucleic acid (PNA), on this context, could be thought of as a possible next-generation scaffold for aptamer synthesis and biomarker sensing, owing to its excessive stability compared to DNA counterparts. On this work, we investigated the efficiency of a sequence of PNA aptamers for monitoring of a outstanding cardiac biomarker, cardiac troponin I (cTnI), utilizing floor plasmon resonance (SPR) and confirmed that PNA sequences shorter than these beforehand reported for DNA can exhibit picomolar affinity, offered the important structural options are preserved. Two totally different immobilization methods (covalent and non-covalent) are validated in parallel for PNAs. The soundness of sensor response within the presence of endonucleases corresponding to DNase I used to be investigated additional, as their incidence in blood, plasma, and serum hydrolyses phosphodiester bonds and might be a limiting issue for point-of-care (PoC) utility of DNA aptamers. Owing to their unnatural spine, PNAs exhibited increased stability in opposition to DNase I compared to their DNA aptamer counterpart. Moreover, molecular dynamics (MD) simulations of DNA and PNA aptamers revealed similarities of their secondary constructions, in addition to distinctions of their propensity to undertake compact conformations. Total, our findings not solely offered a complete framework for PNA design, floor functionalization, and cTnI biomarker detection utilizing PNA-based bio-recognition scaffolds but in addition substantiated the biostability of PNAs, suggesting their excessive relevance for future PoC diagnostic purposes.
