The present invention provides multifunctional nanoconjugates and methods of using them to destroy biological and chemical agents. The nanoconjugates include a dye-coated metal oxide nanoparticles conjugated to a substance capable of binding specifically or non-specifically to an agent. Specifically, the nanoconjugates can be photoactivated by visible light to degrade and destroy biological agents, such as but not limited to bacteria and viruses.
