Water-powered Cu@MoS2 micromotor swarm for a collaborative oscillation of living cells

Summary

A Cu@MoS₂ microtube-based micromotor with a unique composite structure in which MoS₂ was "wrapped" on the surface of Cu microtubes confers excellent photoresponsive properties due to the unique hybridized structure. Micromotor swarms demonstrate spontaneous oscillatory motion in pure water with constant light input, without any external field changes or energetic toxic fuels. This macroscopic periodic oscillatory motion synchronized with the cycle of increasing and decreasing protons (H⁺) produced by the micromotor. The H⁺ gradient is the core of cellular ATP (adenosine triphosphate) synthesis and decomposition. Oscillating proton signals released by the micromotor can be coupled to cardiomyocytes to achieve synchronized oscillations of cell membrane potential/calcium ions and to initiate ATP hydrolysis in cardiomyocytes. The oscillatory behavior was considered to be caused by the different conversion levels of bistable reactions or by non-linear kinetics and mass transport. Specifically, MoS₂ photocatalytic hydrogen production, MoS₂ hydrolysis reactions, dynamic diffusive matter exchange from electroosmotic flow, and interfacial effects contribute to this phenomenon.