Chemoplasmonic Oscillation: A Chemomechanical Energy Transducer

Chemical oscillations and waves are nonequilibrium systems that sustain a steady state with constant energy input of reactants like the life systems. Most of these oscillations are theoretically and fundamentally exploited but how to mimic the energy convolution of biological systems remains elusive. Here we develop a chemomechanical energy transducer (CoMET) based on gold nanoparticles (Au NPs) and thermo-/pH-responsive polymers, which transforms the trapped chemical energy into a tangible mechanical oscillation probed by extinction spectra. Our results show that the mechanical movement of Au NPs characterized by the chemoplasmonic oscillation follows exactly the pH oscillation and can be tuned by changing the temperature and the injection rate of the reductants. It is revealed that the energy input of the redox potentials which later converts to the collective (dis-)aggregation of Au NPs is the main driving force of the chemoplasmonic oscillation. The energy efficiency (similar to 34%) and force generation (similar to 28 pN) of this CoMET outperforms many biochemomechanical systems, which offers an alternative means to power the nanomechanics and nanomachines.