Fig. 3. PA images (snapshot at 730 nm) of the tube phantoms containing 3-M, dilution series (to the conc. in Table 1) (A) 20× dilution in DMF (i.e. conc. (in μM) of 3-2H = 3.2, 3-Zn = 4.6, 3-Ni = 6.2, 3-Cu = 5.3 and 3-Co = 5.8), (B) 40× dilution in DMF (i.e. conc. (in μM) of 3-2H = 1.6, 3-Zn = 2.3, 3-Ni = 3.1, 3-Cu = 2.7 and 3-Co = 2.9).
