What kind of UVA can be used for sterilization?

First of all, UV-C can kill bacteria. Since the wavelength of UV-C is 200-280nm, it is invisible to the human eye, so it is also called "invisible light sterilization".

 

A certain band in UV-A also has the function of sterilization and disinfection. This band is around 405nm. Because it is visible to the human eye, it is also called "visible light sterilization"


Comparison of the sterilization principle of UV-A and UV-C

UV-A oxidation changes properties

 

●Photosensitive molecules such as riboflavin and porphyrin in bacterial cells can absorb specific light energy in UV-A

●Bacterial cells are oxidized to form active molecules such as OH-, O2-, O2

●Bacterial cell wall is damaged and killed

哪種 UVA 可以用來殺菌消毒呢?

首先,UV-C 可以殺菌。由於 UV-C 的波段在200-280nm,人眼不可見,因此又叫“不可見光殺菌”。

UV-A 中的某一特定波段也具有殺菌消毒功能,這個波段在405nm附近,由於人眼可見,因此也稱為“可見光殺菌”


UV-A與UV-C的殺菌原理對比

UV-A 氧化改變性質

 

 

●細菌細胞中的核黃素和卟啉等光敏性分子可吸收UV-A中特定的光能量

●細菌細胞被氧化,形成OH-、O2-、O2等活性分子

●細菌細胞的細胞壁損傷,從而被滅殺