TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: In the method, wooden plank of 500 mm length, 70 mm width and 20 mm thickness was used as the assembly base. Preferred Method: The method comprises: designing transmitting optical axis through which light at 75 mm height from the base, inserting UV LED in to thermocol sheet to align with the optical axis, and facilitating the independent movement of light source in X-Z plane, constructing moving platform for free movement of light source in Y plane, constructing 3 frames at height of 140 mm separated by 25.4 mm from each other in which housing of lenses were carried out, where first and third frames are consisted of convex lenses which is used to focus the light, second frame consisted of band-pass filter which is used to filter out the light of 401 nm wavelength and reflect out the remaining wavelengths of light, the 3 frames are aligned in such a way that the center of lenses and band-pass filter matched with the optical axis of the assembly, and the 3 frames are constructed at a distance of 140 mm from the light source, designing reaction vessel holder at distance of 100-105 mm from the 3 frame so that light should focus on the center of the reaction vessel, constructing holder such that the center of reaction vessel was aligned with the optical axis of the assembly, providing tightening screw which is fixed the reaction vessel at a specific location, facilitating free movement of reaction vessel in the Y plane, inserting photodetector in to a thermocol sheet to align with the optical axis, and facilitating the independent movement of photodetector in X-Z plane, mounting pin photodiode on copper cladded board and its one end was connected to the power supply (5V direct current source), while the other end was connected to the digital panel meter, mounting UV LED on general purpose pollution control board. The method comprises: growing Flavobacterium sp. cells in 200 ml Luria broth up to 1.9 optical density at lambda max of 600 nm, harvesting cells by centrifugation at 5000 x g for 10 minutes and washing twice with 0.2 M bicarbonate buffer (pH 8.7), finally resuspending the pellet in one-tenth volume in bicarbonate-carbonate buffers and storing at 4 degrees C, and cutting glass fiber fitter discs in semicircular pieces and then transferring in Petri plates where the cell loading was carried out; loading 70 mu l aliquot of harvested cells of 16-24 hours grown culture on each disc and air dried at room temperature for 1 hour, varying concentrations of 150 mu m, and -450 mu m and preparing methyl parathion pesticide, where first only a single semicircular glass fiber filter discs immobilized with cells are inserted in different concentration tubes, absorbance of each tube is measured at 401 nm by UV-visible spectrophotometer, after an incubation period of 30 minutes, and than four semicircular glass fiber filter discs are immobilized with cells and repeated the above procedure, and absorbance are recorded and the effect of varied cell loading was studied for immobilization. The method comprises: arranging the assembly at the start, and fixing all the electrical and optical components at respective positions, where first light was incident on the empty reaction vessel and position of photodetector was adjusted where the maximum focusing of light was seen, and fixed position was assigned to both the light source and the photodetector; calibrating optics biosensor; and pouring the buffer in the reaction vessel and the reading on dew point meter (DPM) is recorded, where buffer is used to get a baseline for studying p-nitrophenol solution, and now studying p-nitrophenol solutions of varying concentrations are poured in reaction vessel one by one and corresponding readings are noted, finally the pesticides solution are poured in the reaction vessel and the cells immobilized on glass fiber filter is inserted with the help of knobs, the light is made to incident on the reaction vessel and the respective absorbance readings were recorded, after a certain time of incubation, the study of growth curve of Flavobacterium is carried and the results of growth curve for Flavobacterium species are studied, from 0-16 hours and the growth curve is in exponential phase, after that it approaches towards stationary phase, and the cells grown at 16 hours has absorbance of 1.9 at lambda maximum of 600 nm. The method comprises studying the effect of cell loading on varying concentrations of methyl parathion, where both the graphs of cell loading on single disc and four discs are linear in nature, thus it is interpreted that cell loading on four discs shows higher organophosphorus hydrolase (OPH) activity as compared to cell loading on single disc, and microbial OPH activity is recorded at 401 nm.