| Spores of airborne fungal diseases are large,small and light in weight.Once they cause disease,it is difficult to take effective control measures.Therefore,rapid and accurate detection of pathogenic fungal spore types and quantities is critical for early prediction and real-time warning of airborne diseases.However,due to the low levels of disease spores in the air and interference from contaminants,traditional detection methods usually require sampling prior to detection,and the entire process is complex and slow.Given the above problems,this paper comprehensively combs,summarizes the relevant research on microbial capture and detection technology of airborne diseases at home and abroad.On this basis,a method of disease spore identification based on gas flow scattering photon counting composite spectrum clustering on chip(microfluidic chip)is proposed,and the key content of this method is explored theoretically and experimentally.The specific research content of the paper is as follows:(1)Based on the physicochemical properties and dynamic laws of gas-borne spores in microchannels,the principle and separation model of spores in microfluidic focusing are analyzed,and an axial gas sheath flow coupled radial sheath flow control spore focusing and separation method is proposed;(2)The microfluidic chip was designed that integrates axial double sheath spore focusing and radial sheath separation functions after we reasonably select and optimize the chip area structure;COMSOL numerical simulation method was used to explore the effects of intersection angle,axial and radial gas sheath flow on precise spore manipulation;and then we select suitable materials to prepare chips.(3)The distribution of scattered light effects and select appropriate scattered photons to measure the angle was studied;based on the variation law of the number of scattered photons by flowing spores,a photon peak spore size model is established to explore the coupling relationship between photon peak number and spore number,and a flow airborne spore counting method is proposed.(4)Based on the movement position and spectral change law of different species of spores,spectral information of characteristic bands was extracted,and interspecific clustering was established.Combined with species discriminative model,spectral recognition of flow type mixed spores was studied.Through numerical simulation and the selection of three different types of spores(Rice smut spores,Aspergillus niger spores,and Aspergillus charcoal spores)as the main objects for experiments,the results showed that a sufficiently long focusing flow could be maintained when the intersection angle was 10 °.The fixed spore inlet velocity is 2.5m L/min,and the required focusing width and spore separation effect can be achieved when the axial and radial gas sheath flow velocities are controlled at 12 and10 m L/min,respectively;The maximum received light intensity occurs when the angle between the photon counter and the incident light is 90 °.Compared with traditional microscopic counting,on-chip flow scattering photon counting has higher accuracy and smaller standard deviation;In terms of flow spectrum spore clustering recognition,inter species clustering and recognition of spores can be achieved based on Principal Component Analysis(PCA)and Partial Least Squares Discriminant Analysis(PLSDA),with an accuracy of 95.1%.The setting of flow spectrum analysis provides highprecision real-time particle clustering recognition. |
PDF Full Text Request