Aptamer-conjugated nanoparticles: emerging nano-enabled platforms for rapid and sensitive detection of viral infections.

During the recent outbreak of SARS-CoV-2, the global healthcare system experienced firsthand the importance of accurate and rapid detection techniques in the containment of pandemic situations. Conventional viral detection techniques, although highly specific, often suffer from slow, labour-intensive workflows that limit their applicability for rapid diagnosis. Moreover, their reliability can be compromised by factors such as inadequate technical expertise and improper sample handling, potentially leading to erroneous results. When the global public health system is continuously struggling to control viral diseases like dengue, influenza, hepatitis B, and acquired immunodeficiency syndrome, cutting-edge nanotechnology and biosensor-enabled next-generation diagnostic platforms have shown improved analytical performances. Among these, aptamer-conjugated nanoparticles (ACNPs) have emerged as a promising nanosystem that integrates the high molecular recognition capability of aptamers with the unique physicochemical and optical properties of nanoparticles. Aptamers are short, single-stranded DNA, RNA, or peptide sequences that offer remarkable affinity and selectivity toward diverse viral biomarkers, including proteins, nucleic acids, and intact virions. Their conjugation with nanoparticles imparts superior stability, signal amplification, and biofunctional versatility under physiological conditions. These hybrid systems demonstrate substantial potential in biosensing, bioimaging, and providing enhanced diagnostic precision. This review aims to present the fundamental design principles of ACNP-based detection strategies and to highlight recent advances in viral diagnostics. Additionally, it underscores the underlying sensing mechanisms and analytical advantages, and discusses the current challenges associated with ACNP-enabled diagnostic platforms.