Three-dimensional (3-D) microfluidic-channel-based DNA biosensor for ultra-sensitive electrochemical detection

A three-dimensional (3-D) microfluidic-channel-based electrochemical DNA biosensor was constructed using anodic aluminum oxide (AAO) filtration membranes as the designing template by taking advantage of their well-defined cylindrical fluidic channels. Cyclic voltammetry (CV) measurements indicated that the microfluidic-channel-based DNA biosensor showed detection sensitivity amplified to 10−19 M, which is one order of magnitude higher than attomolar (10−18 M) range. Such enhanced detection sensitivity is attributed to the well-defined fluidic channel structure that gives high surface area for probe DNA immobilization and enables target DNA solutions to pass through its fluidic channels for rapid and efficient hybridization.