Fig. 2

Synthesis, characterization, and uptake of AuNRs. A Schematic illustration of the seed-mediated method for the growth of AuNRs. Reproduced with permission from Ref. [17]. Copyright 2013, Royal Society of Chemistry. B (a) The AuNRs intrinsic structure was characterized by high-resolution transmission electron microscopy as a single crystal along the [001] long axis. Reproduced with permission from Ref. [23]. Copyright 2019, Oxford University Press. (b) The UV–Vis absorbance of colloidal gold nanoparticles at 400 nm can determine Au concentrations in colloidal gold solutions. Reproduced with permission from Ref. [26]. Copyright 2014, ACS Publication. (c) A picture of the dynamics of vertically aligned assemblies of AuNRs. Reproduced with permission from Ref. [27]. Copyright 2020, ACS Publication. (d) UV–Vis-NIR extinction spectra of AuNRs with aspect ratios (AR) 1.5–3.5, AR are indicated above the absorbance spectrum of each sample. Reproduced with permission from Ref. [5]. Copyright 2021, Frontiers Media S.A. C Illustration of several factors affecting the cellular uptake of AuNRs. Reproduced with permission from Ref. [5]. Copyright 2021, Frontiers Media S.A.