A reusable and label-free supersandwich biosensor for sensitive DNA detection by immobilizing target-triggered DNA concatamers on ternary self-assembled monolayer

- Reusable and signal-on electrochemical sensor was developed.
- The label-free and enzyme-free strategy greatly depressed the detection cost.
- A target-dependent supersandwich mechanism showed outstanding selectivity.
- A ternary self-assembled monolayer strategy greatly improved the reproducibility.
- A dumbbell-shape DNA was used to recognize target-DNA.