Figure 1.

(A) Schematic of polydopamine nanoparticle (PDA NP)-mediated photothermal stimulation of neurons. PDA nanoparticles localized on the neuron membrane, modulates the neural activity through photothermal conversion of NIR light. (B) SEM image, (C) DLS measurement and (D) Absorption spectra of PDA NPs. (E) Temperature changes in PDA NP solution with different concentrations at 14 mW mm⁻² laser power density. (F) Temperature changes in 100 μg ml⁻¹ solution of PDA NP at different laser power density and (G) Corresponding IR camera images of the PDA NP solution at the end of the laser illumination period.