Aptamer-carbon Nanotube Hybrids: Emerging Frontiers in Biomedical Diagnostics and Therapeutics

Aptamers are single-stranded DNA or RNA molecules that exhibit remarkable affinity and specificity for a broad spectrum of biological targets, positioning them as compelling alternatives to antibodies in both diagnostics and therapeutics. Their ease of synthesis, chemical stability, and tunable binding properties make them highly adaptable for molecular recognition applications. Carbon Nanotubes (CNTs), on the other hand, are renowned for their unique structural, electrical, optical, and mechanical properties, ultimately providing an ideal nanoscale scaffold for aptamer conjugation. When combined with aptamers, CNTs form multifunctional hybrid nanoplatforms that merge the molecular selectivity of aptamers with the high surface area, conductivity, and mechanical strength of CNTs. This review discusses the fundamental concepts, functionalization strategies, and biomedical potential of aptamer-CNT hybrids. Both covalent and non-covalent conjugation approaches are examined, highlighting their impact on stability, sensitivity, and biocompatibility at the biointerface. Recent progress in molecular recognition, biosensing, targeted drug delivery, imaging, and theranostic applications is also summarized. Particular attention is given to the role of CNTs in enhancing electron transfer, signal amplification, and controlled therapeutic release. Moreover, diagnostic and therapeutic applications across various disease models, including cancer, infectious diseases, and neurodegenerative disorders, are highlighted. Furthermore, emerging challenges related to the toxicity, biodegradability, and pharmacokinetics of CNT-based hybrids are addressed, while considering regulatory and ethical perspectives that govern their clinical translation. Overall, aptamer-CNT hybrids hold immense promise as versatile, tunable, and multifunctional platforms that could fundamentally transform next-generation precision medicine and nanotherapeutic systems.