Integrated microfluidic electrochemical DNA sensor.

Effective systems for rapid, sequence-specific nucleic acid detection at the point of care would be valuable for a wide variety of applications, including clinical diagnostics, food safety, forensics, and environmental monitoring. Electrochemical detection offers many advantages as a basis for such platforms, including portability and ready integration with electronics. Toward this end, we report the Integrated Microfluidic Electrochemical DNA (IMED) sensor, which combines three key biochemical functionalities--symmetric PCR, enzymatic single-stranded DNA generation, and sequence-specific electrochemical detection--in a disposable, monolithic chip. Using this platform, we demonstrate detection of genomic DNA from Salmonella enterica serovar Typhimurium LT2 with a limit of detection of <10 aM, which is approximately 2 orders of magnitude lower than that from previously reported electrochemical chip-based methods.