Rapid and Controllable Design of Robust Superwettable Microchips by a Click Reaction for Efficient o-Phthalaldehyde and Glucose Detection.

Superwettable patterns with superhydrophobic and superhydrophilic units have the capacity of enriching and absorbing microdroplets for multifunctional biosensing. Combining the advantages of superwettable micropatterns and a rapid click reaction, we first prepared a film using propargyl methacrylate-ethylene dimethacrylate and then created a superhydrophobic-superhydrophilic micropattern by a rapid thiol-yne click reaction. Due to the high wettability contrast, water droplets tend to be anchored in the superhydrophilic region. Molecules dissolved in a water droplet are therefore uniformly enriched in the superhydrophilic region after evaporation because of the Malangoni effect. This provides a rational strategy to develop novel patterned microchips for sensing applications. Combining with fluorescence imaging technology, the Ti superwettable microchip can be used to detect o-phthalaldehyde in water, with a detection limit as low as 10-7 mol L-1. In addition, taking advantage of the oxidative color rendering ability of glucose, the microchip, when fabricated on a glass substrate, can realize reuseable glucose detection with a detection limit of 2 mM within 15 min.