Hybridization-Based Electrochemical Biosensors for RNA Detection: Key Concepts and Insights.

Electrochemical biosensors (E-biosensors) represent a promising platform for the detection of biomolecules closely linked to human health. Among these, RNA targets are of particular importance, including viral RNA (essential for disease diagnostics and epidemiological monitoring) and microRNAs (miRNAs), which serve as biomarkers for disease progression and treatment response. Among the different E-biosensor designs, hybridization-based sensors rely on capture DNA probes to recognize target RNA, offer high selectivity and sensitivity through electrochemical readouts. This review summarizes recent advances in the design of hybridization-based E-biosensors for viral RNA and miRNA detection. Key aspects discussed include probe architecture, electrode materials, enzyme-free signal enhancement strategies, and amplification methods with a focus on isothermal approaches. Current challenges and future directions are also highlighted, providing a guide for researchers developing next-generation E-biosensors for RNA detection.