Surface Disinfection on Non-porous Coupons using TiO2 with UV

The ongoing COVID pandemic has opened the doors for the development of effective surface disinfection technologies. UV technology is one of the most effective technique to be used in combination with different photocatalytic agents such as Titanium Dioxide (TiO2) for microbial inactivation. There are many bacteria and viruses which have the potential to infect humans via surface-oral/inhalation pathway. Thus, it is important to evaluate the effectiveness of these techniques used to inactivate microorganisms to minimize environmental transmission. UV light directly acts on bacteria and viruses by damaging their nucleic acids and protein structures. TiO2 acts as a photocatalyst, generates hydroxyl radicals under UV, leading to enhanced inactivation efficacy. This study focuses on the impact of UVC light at 254 nm wavelength in combination with spray formulations with TiO2 for the inactivation of E. coli (exposure times of 1, 5 and 10 minutes) and bacteriophages P22 (exposure times of 5 and 10 minutes) and MS2 (exposure times of 1 and 5 minutes). This study includes tests that explored the long-lasting impact of spray formulations on non-porous surface. Minimal inactivation of ~ 0.15 log inactivation of E. coli was resulted using TiO¬2 alone but when UV was added to the procedure on average 3 log inactivation was achieved. It was noted that MS2 was found to be more susceptible to UV as compared to P22 due to its higher inactivation rate. The spray formulation homogeneity is a critical factor in consistent microbial inactivation. In addition, the UV intensity of the handheld device is an important factor for total disinfection. However, the combined spray formulation and UV technology is an effective method of surface disinfection.