An autonomous bio-barcode DNA machine for exponential DNA amplification and its application to the electrochemical determination of adenosine triphosphate.

A novel autonomous bio-barcode DNA machine that is driven by template-dependent DNA replication is developed to exponentially amplify special DNA sequences. Combined with a DNA aptamer recognition element, the DNA machine can be further applied in the aptamer-based, amplified analysis of small molecules. As a model analyte, adenosine triphosphate (ATP) is determined by using the DNA machine system in combination with a DNA aptamer recognition strategy and differential pulse anodic stripping voltammetry (DPASV). Under the optimum conditions, detection limits as low as 2.8×10(-17) M (3σ) for target DNA and 4.7×10(-9) M (3σ) for ATP are achieved. The satisfactory determination of ATP in K562 leukemia cell and Ramos Burkitt's lymphoma cell reveal that this protocol possesses good selectivity and practicality. As a promising biomolecular device, this DNA machine may have an even broader application in the rapidly developing field of nanobiotechnology.