DNA aptamer-based sensitive electrochemical biosensor for NAD(H) detection.

Nicotinamide-adenine dinucleotide (NAD(H)) plays a critical role in cellular metabolism, and its accurate measurement is essential for elucidating biological mechanisms and disease progression. However, specific recognition probes and sensitive biosensors for NAD(H) remains a significant challenge. Here, we screen an aptamer (NAD3-1a) that exhibits specific binding to NAD(H) with micromolar affinity. By incorporating this aptamer with tetrahedral DNA nanostructure, we develop a highly selective and sensitive electrochemical biosensor for the detection of NAD(H). This biosensor enables precise detection of NAD(H) within a linear range of 10 ∼ 10 M, offering remarkable stability and reproducibility. Utilizing this biosensor, we observed significant variations in the NAD(H) levels between normal and tumor cells, as well as a notable reduction in NAD(H) in the skeletal muscle tissues of aged mice. These results highlight the potential of this aptamer-based biosensor to advance our understanding of metabolic variations in both health and disease contexts.