Nanomaterial-enabled methods for nucleic-acid sensing: biorecognition, transduction, comparative evidence, and...

Early and accurate detection of nucleic acids, particularly DNA, is central to modern diagnostics, environmental surveillance, and biomedical research. Nanomaterial-enabled nucleic-acid biosensors exploit nanoscale physicochemical properties, including high surface-area-to-volume ratio, tunable optical responses, enhanced electron transfer, magnetic enrichment, and catalytic activity, to improve sensitivity, selectivity, response time, and device miniaturization. This review examines nanomaterial-enabled DNA and RNA sensing, distinguishing recognition, amplification, and reporting functions. The principal biorecognition elements, including enzymes, antibodies, nucleic-acid probes, aptamers, and peptides, are discussed, followed by transduction strategies such as surface-enhanced Raman spectroscopy, amperometric, potentiometric, field-effect, conductometric, and impedimetric electrochemical biosensors, and electrical immunosensors. The roles of key nanomaterials, including gold nanoparticles, iron oxide nanoparticles, quantum dots, and graphene, are reviewed as signal-amplification and transduction components. Representative studies are evaluated in terms of limit of detection, linear range, selectivity, and clinical applicability. Because assay conditions differ among studies, reported detection limits are considered together with the sample matrix, amplification method, and validation approach. Particular emphasis is placed on linking material properties, recognition chemistry, and readout mechanisms to practical diagnostic performance. Finally, current challenges, multiplexed quantification, clinical translation, and emerging nanofabrication strategies for next-generation biosensors for point-of-care use are highlighted. This article is a critical narrative review; the databases, exact search strings, eligibility criteria, screening procedure and record counts used to assemble the surveyed corpus are reported, and a study-level inventory is provided in the SI.