Fig. 1. Fabrication and characterization of Re NCs. (a) TEM image; (b) DLS distribution; (c) FTIR spectra of Re NCs and PEG-SH; (d) UV-vis-NIR absorption at different time points during fabrication; inset is a digital image of Re NC dispersions modified with different kinds of PEG; (e) UV-vis-NIR absorption of Re NC dispersions at different concentrations; (f) photothermal heating curves of Re NC dispersions at different concentrations and pure water; (g) the heating/cooling curves of Re NCs (250 ppm) under laser irradiation (2 W, 808 nm); (h) the fitting linear curve of time data vs. –ln θ from the cooling period of Re NCs.