講演情報
[14a-K205-5]Fast and reliable water toxicity monitoring using a novel biospeckle approach
〇(PC)Devi Arti Devi3, Hirofumi Kadono1, Uma Maheswari Rajagopalan2 (1.Graduate School of Science and Engineeing Saitama University, 255 shimookubo, Sakura ward, Saitama, 338-0825, Japan, 2.Department of mechanical Eng. Faculty of Engineering, Shibaura Institute of Technology, Japan, 3.Department of Applied Chemistry, Shibaura Institute of Technology, Japan)
キーワード：
Biospeckle、water pollution、Bioassay、microorganisms、water toxicity、organic solvent
Recently, the direct toxicity assessment (DTA) approach or bioassay has attracted much attention as it can comprehensively evaluate water toxicity without examining a specific/individual chemical component. Bioassays are used to investigate how organisms respond to pollutants compared to controls. In this technique, a microscope observation is required to know the critical features such as alive/dead, and swimming ability of microorganisms. As the size of the microorganism becomes smaller, observation becomes more difficult due to the narrower focal depth of the imaging system. In our study, to overcome the difficulties, we proposed a novel technique for the microbioassay utilizing a biospeckle in the diffraction field generated from their movement. In this experiment, P. caudatum, sized 200-300 µm, and E. gracilis, sized 35-30 µm, as microorganisms. The sample cell containing paramecia was illuminated with a laser light with a diameter 15mm and wavelength 635nm. The specular component of the transmitted light was filtered out using a spatial filter placed at the fourier plane and the biospeckle patterns in diffraction field were acquired using CCD camera as a movie. It is obvious that the dynamic properties of the biospeckle precisely reflects the movement of the scattering particles or planktons. The planktons were exposed to acephate (C4H10NO3PS), a water-soluble organophosphorus insecticide widely used for pest control on crops, ornamental plants, and in food handling areas. Its primary metabolite, methamidophos, exhibits significant neurotoxicity and has been shown to impact various aquatic and terrestrial species, highlighting its potential to contribute to water toxicity.