Cellphone-based Intelligent Sensing Technology And Its Research In Rapid And On-site Detection Of Marine Toxins

With the rapid modernization development of human society,the increasing human activities cause the increasingly serious pollution in marine environment.That severely affects the aquaculture industry and foreign trade,even endangers human public safety.Hence,it is necessary for routine monitoring of marine toxins to develop a simple,rapid and point-of-care detection method.Intelligent sensing technology integrates signal acquisition,signal processing and information exchange,which can simulate human sensory function by combining with intelligent detection method.It is non-destructive,quick,easy-to-use,lowcost,high-sensitivity,high-specificity and high-repeatability,and applied in clinical diagnosis,life analysis,food security and environmental protection.Therefore,a small,portable,simple-to-operate optical detection system,which can be combined with biosensing technology and applied in rapid on-spot detection to marine toxins,has huge value in research,application,commerce and public welfare.In this study,the two cellphone-based system,intelligent high-throughput and simultaneous detection system bionic electronic eye(Bionic e-Eye)and hand-held intelligent fast detection optical system,was designed and realized based on photoinduced optical biosensing detection technology.Combing Bionic e-Eye and ELISA realized the high-throughput,rapid and quantitative analysis to shellfish toxins.Moreover,the cell viability biosensor(CVB)regarding living cell as sensing element was combined with Bionic e-Eye to research a novel fast-field analysis method.In addition,two kinds of gold immunochromatography assay(GICA)strips were developed and combined with hand-held intelligent fast detection optical system to research a simple and easily-spread on-site quick testing method to marine toxins.The main content and innovations of this dissertation are given as the following aspects.1.A design method of cellphone-based intelligent detection optical system was proposed,and HSV bionic color model was applied in colorimetric analysis to improve system detection sensitivityBionic e-Eye was design and implemented based on the absorption analysis and image processing technology.Depending on different application scenario,two App,iPlate and iPlate Monitor were developed to the rapid detection and longtime monitoring of chromogenic biochemical reaction,respectively.HSV color model was introduced to promote instrument sensitivity.Moreover,the system performance was tested by the experiments of color intensity longtime stability and bicinchoninic acid protein assay(BCA).The results showed that Bionic e-Eye applied HSV instead of RGB improved sensitivity over threefold.2.A detection method based on the combination of Bionic e-Eye and ELISA was proposed,and it implemented the high-throughput simultaneous fast-field detection of marine toxins.Bionic e-Eye combined with indirect competitive ELISA detected the toxins specifically,with high sensitivity and throughput.Two color models,RGB(red,green,blue)and HSV were compared in detection performance,and the saturability(S)was reached as the best color channel.The system could specifically detect okadaic acid(OA)and saxitoxin(STX)in the range of 0.2?5 ng/mL and 0.02?0.32 ng/mL,respectively.And the limits of detection(LODs)were 0.0854 ng/mL and 0.0092 ng/mL,respectively.The recovery rates were within 95.20?109.72%and 90.19?112.15%,respectively.The strongly direct correlation of Bionic e-Eye and microplate reader that was standard instrument were verified in the detection experiments of recovery and real samples.The system utilized image detection technology to realize high-throughput simultaneous measurement,which could decrease the errors in different wells caused by the traditional mechanical mobile platform.Moreover,the system was applicable to the high-throughput simultaneous fast-field detection of marine toxins due to its low cost,portability and timesaving.3.A detection method based on the combination of Bionic e-Eye and cell-based biosensor was proposed,and it provided a feasible program that had biotoxicity evaluation ability and was used in rapid spot detection of marine toxin.CVB was designed and constructed,then was combined with Bionic e-Eye to research a novel rapid on-spot analysis method having biofunctional evaluation.CVB was a cell-based biosensor that regarded living cell and cell counting kit(CCK-8)as sensing element and transducer,respectively.And it could convert the cell vibility to optical signals.Two kinds of cells,HepG2 and THP-1 were used to construct CVB,respectively.The best cell seeding densities were 4000 cells/well and 8000 cells/well after the experiments of density optimization.The HepG2-CVB and THP-1-CVB could specifically detect OA in the range of 5?200 ng/mL.The best detection point-in-time were 2.87 h and 3.33 h,respectively.The LODs were 3.4083 ng/mL and 13.4456 ng/mL,respectively.The results demonstrated that adherent cell and suspension cell were suitable for the cell selection of CVB.Therefore,that novel method had some features of portability,low cost,easy operating and high efficiency,and it could be applied in fast-filed,high-sensitivity and high-specific detection of marine toxins.4.A combining with GICA strip hand-held intelligent fast detection system was developed,and it satisfied the practical requirements of easy operation in marine toxin fast-field detection.Two kinds of GICA strip were developed to OA and STX detection based on competitive immunoassay.The cellphone-based hand-held intelligent fast detection optical system was designed and realized based on the detection theory of reflection photometer to satisfy the requirements of hand-held,low-cost and on-spot detection instrument from grass roots.The smartphone-based hand-held fast detection optical system combined with GICA strip specifically detect OA and STX in the range of 3?20 ng/mL and 6.25?100 ng/mL,respectively.The LODs were 2.4516 ng/mL and 5.141 ng/mL,respectively.The relative error was within 8%in comparison to ELISA.Comparing with mouse bioassay(MBA)and liquid chromatography-tandem mass spectrometry(LC-MS/MS),the system had some advantages of low cost,high-integration,speed and easy operating.Therefore,the combining with GICA strip hand-held intelligent fast detection optical system was applicable to fast-filed detection of marine toxins and rapid promotion.