Table 2. Spin–spin relaxation rate (1/T₂) of 1 mL γ-Fe₂O₃@Au aqueous solution with and without light irradiation.

1/T2 (s−1)
Iron concentration (mM)	0.21	0.14	0.095	0.048	0.021	0.0021
Light OFF	1.625 ± 0.086	1.345 ± 0.059	1.072 ± 0.045	0.971 ± 0.069	0.873 ± 0.032	0.734 ± 0.025
Light On	1.648 ± 0.073	1.309 ± 0.056	1.115 ± 0.044	0.998 ± 0.042	0.822 ± 0.036	0.773 ± 0.036
P-value	0.4197	0.3357	0.2591	0.3765	0.1521	0.2105

The data are presented as the mean ± SEM from 10 measurements. The P-value is based on single-trail paired t-test calculation.