Microneedle-based detection of nucleic acids in interstitial fluid: A review

Traditional nucleic acid detection methods rely on external sampling and complex, multi-step offline analyses, which result in long turnaround times and require specialized laboratory infrastructure. Recent advancements in microneedle (MN)-based technologies have transformed interstitial fluid (ISF) sampling by enabling minimally invasive and real-time monitoring of biomarkers. This review systematically discusses the development of MN-mediated ISF nucleic acid detection platforms, with emphasis on four key areas: (1) The principles and optimization of MN-based ISF sampling, encompassing fabrication techniques and extraction mechanisms such as negative pressure, swelling, and capillary action; (2) Nucleic acid enrichment and amplification strategies specifically adapted for ISF, including isothermal amplification and hybridization-based methods; (3) The development and targeting MN-based nucleic acid sensing tools; and (4) Medical translation and continuous monitoring pose challenges. This review synthesizes recent progress, highlights technical bottlenecks, and offers insights to support the translational development of clinically viable MN-based ISF nucleic acid detection systems for precision diagnostics and chronic disease surveillance.