The precise delivery of nitric oxide (NO) within tumor microenvironments is a promising strategy in anticancer therapy, as NO exhibits dose-dependent cytotoxic effects. Light-activated NO donors offer excellent spatiotemporal control and minimal invasiveness, making them ideal for therapeutic use. Here, we report a water-soluble nanoconjugate, NCDs-1, combining a two-step NO photodonor with blue-emitting, nitrogen-doped carbon nanodots (NCDs). This hybrid nanostructure (~10 nm) displays a new absorption band absent in the individual components, indicating strong ground-state electronic interaction. Upon blue light irradiation, NCDs-1 achieves nearly a tenfold enhancement in NO release compared to the free photodonor, likely due to photoinduced electron transfer between the NCDs and the NO-releasing unit. Notably, its quenched blue fluorescence is restored during the second NO release step, offering a real-time optical signal to monitor NO generation. Alongside efficient NO photorelease, NCDs-1 shows significant photothermal conversion, supporting its application in multimodal therapy. To shift light responsiveness toward more biocompatible wavelengths, we developed a second nanoconjugate, NCDs-2, by altering the solvent during NCD synthesis while using the same precursors (citric acid and urea). This yielded NCDs with absorption shifted into the green region. When conjugated with the same NO donor, NCDs-2 retained excellent NO release under green light—a wavelength with improved tissue penetration and compatibility. Preliminary in vitro studies on cancer cells confirmed the therapeutic potential of both nanoconjugates. These multifunctional platforms represent a promising strategy for light-controlled NO delivery and combined photothermal therapy, with tunable optical properties adaptable to different biological contexts.