Fig. 4. (a) Monitoring the singlet oxygen generation of ZrMOF–aptamer nanoparticles upon irradiating with a 650 nm laser (200 mW cm^–2). (b) Cell viability study of ZrMOF–aptamer and ZrMOF–Library. For ZrMOF–Lib-650, HeLa cells were incubated with ZrMOF–Library nanoparticles and irradiated with a laser at 650 nm. For ZrMOF–Apt only, HeLa cells were incubated with ZrMOF–aptamer nanoparticles without laser irradiation. For ZrMOF–Apt-650, HeLa cells were incubated with ZrMOF–aptamer nanoparticles and irradiated with a laser at 650 nm. Laser power was 200 mW cm^–2. Irradiation time was 5 min.