Paper electrochemical device for detection of DNA and thrombin by target-induced conformational switching

Here, we report a strategy for the design of an inexpensive paper analytical device (PAD) for quantitative detection of oligonucleotides and proteins. Detection is based on the principle of target-induced conformational switching of an aptamer linked to an electrochemical label. This simple and robust method is well matched to the equally simple and robust characteristics of the PAD platform. The demonstrated limits of detection for DNA and thrombin are 30 nM and 16 nM, respectively, and the device-to-device reproducibility is better than ±10%. The PAD has a shelf life of at least 4 weeks, involves little user intervention, and requires a sample volume of just 20 μL.