Fig. 5. (a) Representative confocal colocalization images of mitochondria (stained with MitoTracker Green) in MCF7 cells treated with compound TCy5-CHO (5 μM) for 1 h. For MitoTracker Green and TCy5, emissions were collected at 500–580 nm (λ_ex = 488 nm) and 650–730 nm (λ_ex = 640 nm), respectively. Scale bar = 20 μm. (b) Evaluation of mitochondrial membrane potential using probe JC-1 in MCF7 cells treated with compound TCy5-CHO and irradiated by 660 nm light with a 2 J cm⁻² light dose. For JC-1, emissions are collected at 500–550 nm (λ_ex = 488 nm) and 580–630 nm (λ_ex = 561 nm), respectively. Scale bar = 20 μm. (c) Evaluation of tumoricidal efficacy using calcein AM/propidium iodide (PI) probes in MCF7 cells treated with compound TCy5 and irradiated with 660 nm light at 2 J cm⁻². Cell viability of HepG2 (d) and 4T1 (e) cells subjected to a range of TCy5-CHO concentrations under 10 mW cm⁻² light irradiation for 10 min. (f) PDT effect comparison of TCy5-CHO and commercial Ce6 in MCF7 cells.