Fig. 2

PEGylated AuNPs experienced less spectral shifting and broadening in cells than bare AuNPs, as determined by hyperspectral imaging analysis. a Peak wavelengths of cell ROI spectra following exposure of bare and PEGylated AuNPs to Sk-Br-3 cells. Dotted lines denote the peak wavelength of UV-vis spectra for bare and PEGylated AuNPs in water in the absence of cells. b Spectral width at 95 % maximum intensity after 24 h for bare and PEGylated AuNPs. Error bars indicate SEM. Spectral peak wavelengths were measured from more than 35 cell ROIs for each condition. * indicates statistically significant difference (p < 0.01) based on two-tailed Student’s t test. Data for bare AuNPs are re-plotted here from ref [13] with permission as a reference for comparison with data for PEGylated AuNPs