Abstract

Peptide Nucleic Acid/2D Hybrid Material for Ultrasensitive Enzyme-free Electrochemical Detection of microRNA

Muhsin Ali, Postdoc, King Abdullah University of Science and Technology

MicroRNA (miRNAs) have become highly promising, minimally invasive biomarkers for a variety of pathologies, including cancer and neurodegenerative diseases. However, even with industry-recognized methods like RT-qPCR, their short lengths and low concentrations make them difficult to detect consistently. Here, we provide a novel electrochemical detection approach for microRNA that is devoid of amplification and enzymes and takes use of the specificity of custom Peptide Nucleic Acid (PNA) probes mounted on 2D nanomaterials. These latter materials are 2D nanomaterials with appealing characteristics for electrochemical biosensing, including high conductivity, large specific surface area, good biocompatibility, and crucially, high density of functional groups for biofunctionalization. MicroRNA have emerged as extremely promising minimally invPNAs. PNAs have garnered a lot of attention among xeno-nucleic acid oligomers because they have a better binding affinity, more sequence specificity, and greater stability than their native counterparts. The platform demonstrated tremendous potential in the development of point-of-care biosensors for microRNA and potentially other clinically relevant nucleic acids during the proof-of-concept studies by achieving high sensitivity (aM LOD), high specificity, and a large dynamic range (>6 orders of magnitude). This is, to our knowledge, the first demonstration of a hybrid system, which enables enzyme-free sequence-specific detection of miRNA-141 target biomarker.