Stepwise reagent introduction-based droplet platform for multiplexed DNA sensing.

A stepwise reagent introduction (SRI)-based droplet platform is reported to apply in multiplexed DNA sensing via droplet imaging and manipulation techniques. The feature of SRI-based droplet platform is that the multiplexed DNA measurements are performed simultaneously without the need for expensive optical instruments. This is achieved by sequentially driving five different DNA probes labeled with carboxyfluorescein into the same chip channel to individually form droplet and fuse with target DNAs and graphene oxide droplets. Based on the variation of droplet color and fluorescence intensity, rapidly qualitative and quantitative DNA analysis are realized. The cooperation between SRI mode and droplet platform thus opens up the possibility of greatly simplified DNA sensing in high throughput format without complicated fluorescent labeling and chip design.