A Nondispersive Thermopile Device With an Innovative Method to Detect Fusarium Spores

Early detecting of fusarium spore in the air is highly desired, as it helps to protect crops from the potential of dangerous fungal disease. This paper focuses on developing a method and building a portable, reliable, and affordable device, which can promptly and continuously detect the presence of fusarium spores in the air. Based on the Beer-Lambert law and the distinct infrared absorbance spectrum of substances, a specification logarithm ratio formula for two different wavelengths is developed. This is the main principle of the detection technique and design of the device. In the system, there are two sensitive infrared thermopiles that work on two specific infrared wavelengths, including λ
₁
= 6.09 ± 0.06 μm and λ
₂
= 9.49 ± 0.44 μm. The thermopiles are used to measure the infrared light intensity emitted by an infrared light source (2-22 μm) for thefusarium spore detection analysis. The detection is based on the group distinction coefficient. The Beer-Lambert law also assists in the approximate estimation of the quantity of the spores. For testing the detection ability of the system and the method, besides fusarium spore, other substances, such as sunflower pollen, polyphenol, and starch, were also used in the experiments. The experimental results indicate that the fusarium group-distinction coefficient (1.14 ± 0.15) is distinct from the other investigated substances (pollen: 0.13 ± 0.11, turmeric: 0.79 ± 0.07, and starch 0.94 ± 0.07). The results prove that the system and the proposed method can be used to detect and quantify not only for fusarium but also for other spores, molds, and specific pathogens.