Gao Xiao

Droplets act as individual reactors, is widely used in high-throughput applications, including dPCR, single-Cell sequencing and drug screening. Traditionally, the formation and stability of droplets usually require a fluorinated surfactant. However, this type of surfactant has some limitations: first, the synthesis and purification tend to be complicated and costly. Second, the reverse micelles formed by these surfactants can transport small hydrophobic molecules in the droplets, they often cause the cross contamination of droplet content, this inter-drop leakage greatly damage the accuracy of the assay. Third, the traditional surfactants lack reactive functional groups for immobilization of desired molecules onto droplet inner surfaces. To address these problems, my research focuses on developing an amphiphilic polyphenol-based nanoparticles to replace the traditional surfactants that can be used to create low-cost, stable, bio-compatible droplets for microfluidics-based digital PCR or other high-throughput screening applications. The collagen molecules and polyphenol macromolecule were introduced to construct amphiphilic polymer-based nanoparticles for stabilizing the drops. Because the above molecules have rich active groups, so we can easily change the charge properties of the droplet surface by modifying the particles, thus we can effectively prevent the small molecules with same charge from leaking out of the droplets. Compared with the traditional surfactants, the amphiphilic polymer-based nanoparticles we devoloped not only stop the leakage of small molecules in a droplet, and also provide a sufficiently rigid interface to enable the culture of adherent cells such as fibroblasts and breast cancer cells. This technology offers an inexpensive alternative to traditional copolymer surfactant system with features that could enable new applications for high-fidelity biochemical assays.