961216.fig.005a
(a)
961216.fig.005b
(b)
961216.fig.005c
(c)
961216.fig.005d
(d)
Figure 5: Raman spectrum of gold nanospheres (a) and SERS spectra of PEG-GENs prepared with increasing volumes: 20 μL (b), 50 μL (c), and 100 μL (d) of mPEG-SH polymer, recorded in solution, under NIR excitation. Black spectra are taken in the presence of 1 M salted solution while colored spectra represent the spectra of the nano-probes before the addition of salt.