In 2014, Japanese scientists Isamu Akasaki, Hiroshi Amano and Japanese-American scientist Shuji Nakamura won the Nobel Prize in Physics for their outstanding contributions to the research of blue-light LEDs. This incident greatly inspired Japanese scientists to continue fighting for people's lives in their own research fields. As far as blue LED is concerned, although the term is unfamiliar to the public, it will indeed change the way millions of homes are illuminated.
Recently, a research article published by Tohoku University in Japan in the journal Scientific Reports shows that scientists have found a new direction for the use of blue LEDs. When blue LED is at the correct emission frequency, it evolves into a new, effective, convenient, natural and harmless pesticide. Researchers have discovered for the first time that visible light in the blue region of the spectrum is a deadly weapon for killing pests such as mosquitoes and fruit flies.
1. Different colors of light sources have different insecticidal effects
The Northeastern University research team consisted of four scientists and completed an experiment on the impact of light sources on insects using three types of insects: fruit flies, mosquitoes and flour beetles. During the growth period of the three types of insects from eggs to adults, the researchers illuminated them with colored lights of different intensities at different angles. The experimental results are very interesting. Scientists have discovered that when the light changes from ultraviolet (378 nanometers) to visible blue light (508 nanometers), all insects will be annihilated. However, red light and yellow light are basically unable to harm insects.
2. Apply “light” according to the insect species
What’s more interesting is that the wavelength of light is not exactly consistent with its insecticidal effect. For example, light at around 467 nanometers is more effective at killing fruit flies than any other light source at any wavelength; while light at 417 nanometers has excellent killing power against mosquitoes. This means that each type of insect has its own unique "lethal wavelength", which of course is closely related to their living habits. Mosquitoes are accustomed to flying under strong sunlight and can effectively resist most wavelengths of light sources. However, high-intensity ultraviolet radiation is their death knell. Flour beetles live in a dark environment, and they will become very vulnerable to light changes from 404 nanometers to 467 nanometers. From this point of view, we must take appropriate measures to deal with these insects.
3. Working principle of blue LED
Then what we can’t wait to know is naturally how it works. Although a series of experiments are somewhat beyond the scope of ordinary people's understanding, scholars at Northeastern University believe that the principle of blue LED's insecticidal effect is basically the same as that of ultraviolet irradiation that can destroy cells. Scientists say that blue light and ultraviolet light of specific wavelengths can effectively promote the generation of a molecule called reactive oxygen species (ROS) when irradiating insects. Reactive oxygen species will destroy large areas of cell tissue in the insect's body and eventually cause its death. Although people still don’t know how to use blue LED to make a correct insect killer, at least we can be sure that the light has a significant effect on killing insects. If further research can be carried out, scientists may benefit mankind in a healthy, harmless and low-cost way in terms of food cultivation and disease control.
ANNA