Stabilizing liquid crystal droplets with hydrogel films and its application in monitoring adenosine triphosphate

Liquid crystal droplets have shown unique response performance due to their exclusive optical properties and dispersion. However, the stability of LC droplets during storage and application needs to be improved. Here, we report a novel LC droplet sensing platform to improve the stability of LC droplets significantly. By embedding LC droplets into polyacrylamide hydrogel films, the LC droplets can be preserved for four months without noticeable volume loss and any aggregation even in the absence of surfactant. Interestingly, LC droplets exhibit remarkable stability even in ethanol and N,N-Dimethylformamide aqueous solution. Besides, the mechanical properties of hydrogel film do not reduce after embedding LC droplets. Specifically, the introduction of LC droplets improves the elasticity of the hydrogel film. As a sensing platform, the response performance of the LC droplet-embedded hydrogel film is investigated. After being exposed to ATP solution as low as 1 ng/mL, LC droplets can generate optical signal changes which can be observed by the naked eye. The strategy presented here provides a new sight for the design of LC droplet sensors and contributes to the practical application of LC droplet sensors.