Electrochemical DNA Scaffold-Based Sensing Platform for Multiple Modes of Protein Assay and a Keypad Lock System.

Development of a flexible, easy-to-use, and well-controllable DNA-based sensing platform would provide enormous opportunities to boost molecular diagnosis and signal transduction or information processing. Herein, a duplex DNA scaffold containing a bulge was deployed for the fabrication of a simple and general DNA-based electrochemical sensing platform. It could be harnessed for different signal output behaviors (one signal-off and two signal-on modes) toward a single-step analysis of the target protein. The detection limit toward the target protein could reach about 0.1 nM. Also, it could be used as a streamlined electrochemical workflow for the successive monitoring of protein binding. Furthermore, such an electrochemical sensing platform could be explored for the operation of the concatenated AND logic gates as a molecular keypad lock system. The current sensing platform based on only one duplex DNA scaffold presented features such as simple biosensor design and fabrication, flexible operation for different signal outputs, sensitive and selective protein detection, and expandable logic operation. It thus would pave a broad road toward the development of high-performance biosensors or logic devices to be applied for molecular diagnosis or computing.