Table 1. Optical and photoacoustic properties of 3-M and ICG.

Compd no.	Conc. (μM)	λ max [log(ε)] a	At λ max (PA Avr) b	Rel. PA c
ICG	181	791 (4.97)	2.438	1
3-Co	115	733 (4.44)	2.332	1.4
3-Cu	106	727 (4.64)	3.449	2.4
3-Ni	124	710 (4.37)	2.877	1.7
3-Zn	91	732 (4.73)	3.916	3.2
3-2H	63	706 (4.51)	2.344	2.7

^aCalculated from the UV/vis measurements of the diluted solutions (4 times for 3-M and 16 times for ICG) in DMF.

^bThe observed PA Avr in a tube phantom (0.31 mm i.d.).

^cFound by normalizing the PA Avr values with the concentration and dividing all of the values with the normalized PA Avr/conc. value for ICG.