Vanadyl Naphthalocyanine-Doped Polymer Dots for Near-Infrared Light-Induced Nitric Oxide Release and Bactericidal Effects

The development of efficient antibacterial agents is important for public health. To completely damage bacteria in situ, light has been used as an external stimulus, but the wavelength range of light is limited up to visible light at which the antimicrobial activity is incomplete. Here, we report on our investigation of the bactericidal effect of heat and nitric oxide (NO) generated simultaneously by near-infrared (NIR) light using vanadyl naphthalocyanine-doped polymer dots (P-dots). P-dots co-doped with vanadyl naphthalocyanine and N-nitroso compounds generated heat and released NO upon NIR light irradiation. The amount of NO released was dramatically enhanced owing to the ease of bond dissociation in N-nitroso compounds in the presence of generated heat. The anti-bacterial effect of P-dots on Staphylococcus epidermidis and Pseudomonas aeruginosa was clearly caused by heat and NO, demonstrating the potential use of P-dots as antimicrobial agents.