Microorganism adhesion and the resulting contamination of the biomaterial is one of the major causes of biomedical device failure. Stimuli-responsive materials based on dynamically regulating interactions with reversible characteristics of on-off states have attracted increasing attention. Here, a facile self-assembled biomaterial nanocoating constructed using acidity- and photoregulated spiropyran-modified nanoparticles was developed for reversibly regulating bacteria or mammalian cell adhesion-and-detachment. The coating was formed by coating a solution of spiropyran-conjugated nanoparticles around the surface of a silica gel followed by curing and drying at 60 °C for 30 min. Importantly, efficient adhesion-and-detachment of bacteria or cells could be controlled even after 8 cycles owing to the excellent acidity- and light-switched ability. Collectively, this well-defined self-assembled nanocoating as a dynamical and reversible agent provides promising insight for the development of biomedical devices, especially for biomaterial medical coatings.