An electrochemical DNA biosensor based on denatured vesicle-mediated chain exchange amplification combined with electric field-assistance for nucleic acid detection†

Abstract

Electrochemical DNA biosensors have been extensively used in food safety, clinical medicine and environmental monitoring due to their high specificity and sensitivity. However, electrochemical DNA biosensors based on nucleic acid hybridization still face challenges in achieving rapid and sensitive detection. In this study, a sensitive and rapid electrochemical DNA biosensor was developed using Strand Exchange Amplification (SEA) technology, with its performance evaluated against the bovine genome as the target. Additionally, gold nanoparticles (AuNPs) were employed to modify the electrode surface, a strategy to enhance both the density of probe modification and the amplification efficiency. Furthermore, the biosensor's sensitivity has been shown to be augmented by the exceptional conductivity of AuNPs. Despite the biosensor's simplicity and sensitivity, the detection time remains a limiting factor. To address this, the incorporation of an electric field within the biosensor framework has been proposed as a strategy to enhance the coupling rate of the nucleic acid amplification and streptavidin–biotin systems. This modification is anticipated to reduce the overall detection time, enabling rapid and precise real-time nucleic acid analysis. The biosensor demonstrated the capability to detect genome DNA as low as 1 fg μL⁻¹ within 65 min, underscoring its significant potential for applications, such as detecting meat adulteration.