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Development of automatic and efficient immuno-separator of foodborne pathogenic bacteria using magnetophoresis and magnetic mixing

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International Journal of Agricultural and Biological Engineering 2019年第5期12卷 167-172页

作者： Yuhe Wang Gaozhe Cai Maohua Wang jianhan lin Key Laboratory of Agricultural Information Acquisition Technology(Beijing) Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing 100083China Key Laboratory of Modern Precision Agriculture System Integration Research Ministry of EducationChina Agricultural UniversityBeijing 100083China

In recent years,the outbreaks of foodborne diseases caused by pathogenic bacteria have made considerable economic losses and shown a threat to public *** key to prevent and control these diseases is fast screening of pathogenic bacteria,which is usually performed with three procedures:sample collection,bacteria separation and bacteria *** sample collection,the national standard methods are often *** bacteria detection,currently available methods such as Polymerase Chain Reaction and Enzyme linked Immuno-Sorbent Assay are often *** bacteria separation,traditional methods such as filtration and centrifugation are not capable to specifically separate the target ***,food samples are very complicated and require efficient pretreatment for bacteria separation and concentration to achieve accurate and reliable *** conventional immune magnetic separation method can be used to specifically separate the bacteria,but it still cannot meet the requirements for food sample pretreatment due to very low concentration of target bacteria in ***,this study developed an automatic and efficient immuno-separator of foodborne bacteria based on magnetophoresis and magnetic mixing,and *** O157:H7 was used as research model.A magnetic mixer was applied to facilitate the immunoreaction between the immune magnetic nanoparticles and the target bacteria cells,and a magnetophoretic separation tubing was utilized for magnetophoretic separation of the magnetic *** the optimal mixing time of 20 min and the optimal flow rate of 50μL/min,the separation efficiency of *** O157:H7 could be more than 90%,showing that the developed immuno-separator is promising to be applied for efficient separation of foodborne bacteria and can be easily extended for separation of other biological targets by using their specific antibodies.

关键词： foodborne bacteria immuno-separator bacteria separation magnetophoresis magnetic mixing magnetic nanoparticles

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Magnetorheological elastomer and smartphone enable microfluidic biosensing of foodborne pathogen

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Chinese Chemical Letters 2023年第8期34卷 254-258页

作者： Gaozhe Cai Yuhe Wang Yingchao Zhang lingyan Zheng jianhan lin Key Laboratory of Agricultural Information Acquisition Technology Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing 100083China State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Beijing Engineering and Technology Research Center of Food Additives Beijing Technology&Business University(BTBU)Beijing 100048China

Rapid detection of foodborne pathogens is crucial to prevent the outbreaks of foodborne *** this work,we proposed a novel microfluidic biosensor based on magnetorheological elastomer(MRE)and ***,micropump and microvalves were constructed by deforming the MRE under magnetic actuation and integrated into the microfluidic biosensor for fluidic ***,the micropump was used to deliver immune porous gold@platinum nanocatalysts(Au@PtNCs),bacterial sample,and immunomagnetic nanoparticles(MNPs)into a micromixer,where they were mixed,incubated and magnetically separated to obtain the Au@PtNC-bacteria-MNP *** 3,3',5,5'-tetramethylbenzidine and hydrogen peroxide were injected and catalyzed by the Au@PtNCs,smartphone was used to measure the color of the catalysate for quantitative analysis of target *** optimal conditions,this biosensor could detect Salmonella typhimurium quantitatively and automatically in 1 h with a linear detection range of 8.0×10^(1) CFU/mL to 8.0×10^(4) CFU/mL and a detection limit of 62 CFU/*** microfluidic biosensor was compact in size,simple to use,and efficient for detection,and might be used for in-field screening of foodborne pathogens to prevent food poisoning.

关键词： Magnetorheological elastomer Microfluidic chip Colorimetric biosensor Bacterial detection Smartphone image processing

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Rapid and Sensitive Biosensing of Salmonella Using Mechanical Step Rotation and Gold@platinum Nanozymatic Amplification

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Journal of Analysis and Testing 2024年第3期8卷 262-269页

作者： Meixuan Li Lei Wang Ai Xu Ying Ding Fengzhen Yang Yanbin Li jianhan lin Key Laboratory of Agricultural Information Acquisition Technology Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing100083China Center of Excellence for Poultry Science University of ArkansasFayettevilleAR72701USA

Inspired by ballpoint pen,an optical biosensor is developed for detection of Salmonella using a mechanical step rotator with a dropper to greatly simplify operation,a high gradient magnetic field with immune magnetic nanobeads to specifically separate bacteria,and immune gold@platinum nanozymes with a smartphone to sensitively detect ***,the preloaded bacterial sample is drawn by the dropper to react with the immune magnetic nanobeads through repeated squeezing and releasing of the dropper,and the rotator is successively rotated and the dropper is repeatedly squeezed and released to achieve mixing of the bacteria,magnetic nanobeads and gold@platinum nanozymes,followed by magnetic separation to remove the ***,the conjugates are effectively washed with skim milk and ultrapure water,and the substrate are rapidly catalyzed into the ***,the blue product is photographed and analyzed using a smartphone to obtain the Salmonella *** biosensor could detect Salmonella as low as 56 CFU/mL in~25 min.

关键词： optical biosensor mechanical step rotator gold@platinum nanozyme magnetic grid separation Salmonella detection

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A portable viable Salmonella detection device based on microfluidic chip and recombinase aided amplification

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Chinese Chemical Letters 2023年第2期34卷 268-273页

作者： Wuzhen Qi Siyuan Wang Lei Wang Xinge Xi Shangyi Wu Yanbin Li Ming Liao jianhan lin Key Laboratory of Agricultural Information Acquisition Technology Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing 100083China Department of Biological and Agricultural Engineering University of ArkansasFayetteville 72701United States College of Veterinary medicine South China Agricultural UniversityGuangzhou 510642China

creening of foodborne pathogens is important to prevent contaminated foods from their supply chains.n this study, a portable detection device was developed for rapid, sensitive and simple detection of viable almonella using a finger-actuated microfluidic chip and an improved recombinase aided amplification (RAA) assay. Improved propidium monoazide(PMAxx) was combined with RAA to enable this device to distinguish viable bacteria from dead ones. The modification of PMAxx into dead bacteria, the magnetic xtraction of nucleic acids from viable bacteria and the RAA detection of extracted nucleic acids were performed using the microfluidic chip on its supporting device by finger press-release operations. The fluorescent signal resulting from RAA amplification of the nucleic acids was collected using a USB camera nd analyzed using a self-developed smartphone App to quantitatively determine the bacterial concenration. This device could detect Salmonella typhimurium in spiked chicken meats from 1.3 × 10^(2) CFU/m L o 1.3 × 10^(7) CFU/m L in 2 h with a lower detection limit of 130 CFU/m L, and has shown its potential for on-site detection of foodborne pathogens.

关键词： Finger-actuated microfluidic chip PMAxx Recombinase aid amplification Smartphone App Viable bacterial detection

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A lab-on-a-disc platform based on nickel nanowire net and smartphone imaging for rapid and automatic detection of foodborne bacteria

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Chinese Chemical Letters 2022年第4期33卷 2091-2095页

作者： Xiaoting Huo Lei Wang Wuzhen Qi Na Rong Yingjia Liu Siyuan Wang Hong Duan jianhan lin Key Laboratory of Agricultural Information Acquisition Technology Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing 100083China Key Laboratory of Modern Precision Agriculture System Integration Research Ministry of EducationChina Agricultural UniversityBeijing 100083China

Foodborne pathogenic bacteria have been considered as a major risk factor for food safety. It is of great significance to carry out in-field screening of pathogenic bacteria to prevent the outbreaks of foodborne diseases. In this study, a portable lab-on-a-disc platform with a microfluidic disc was developed for rapid and automatic detection of Salmonella typhimurium using a nickel nanowire(Ni NW) net for effective separation of target bacteria, horseradish peroxidase nanoflowers(HRP NFs) for efficient amplification of biological signals, and a self-developed smartphone APP for accurate analysis of colorimetric images. First,the microfluidic disc was preloaded with reagents and samples and centrifuged to form one bacterial sample column, one immune Ni NW column, one HRP NF column, two washing buffer columns and one tetramethylbenzidine(TMB) column, which were separated by air gaps. Then, a rotatable magnetic field was specifically developed to assemble the Ni NWs into a net, which was automatically controlled by a stepped motor to successively pass through the sample column for specific capture of target bacteria, the HRP NF column for specific label of target bacteria, the washing columns for effective removal of sample background and non-specific binding NFs, and the TMB column for colorimetric determination of target bacteria. The color change of TMB from colorless to blue was finally analyzed using the smartphone APP to quantitatively determine the target bacteria. This lab-on-a-disc platform could detect Salmonella typhimurium from 5.6 × 10^(1) CFU/20 μL to 5.6 × 10^(5) CFU/20 μL in 1 h with a lower detection limit of 56 CFU/20 μL. The recovery of target bacteria in spiked chicken samples ranged from 97.5% to 101.8%. This portable platform integrating separation, labeling, washing, catalysis and detection onto a single disc is featured with automatic operation, fast reaction, and small size and has shown its potential for in-field detection of foodborne pathoge

关键词： Lab-on-a-disk platform Nickel nanowire net Horseradish peroxidase nanoflowers Smartphone Bacteria detection

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A microfluidic biosensor for rapid detection of Salmonella typhimurium based on magnetic separation,enzymatic catalysis and electrochemical impedance analysis

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Chinese Chemical Letters 2022年第6期33卷 3156-3160页

作者： Yingjia Liu Dong Jiang Siyuan Wang Gaozhe Cai Li Xue Yanbin Li Ming Liao jianhan lin Key Laboratory of Agricultural Information Acquisition Technology Ministry of Agriculture and Rural AffairsChina Agricultural UniversityBeijing 100083China Department of Biological and Agricultural Engineering University of ArkansasFayettevilleAR 72701United States College of Veterinary medicine South China Agricultural UniversityGuangzhou 510642China

Rapid screening of foodborne pathogens is of great significance to ensure food safety.A microfluidic biosensor based on immunomagnetic separation,enzyme catalysis and electrochemical impedance analysis was developed for rapid and sensitive detection of ***,the bacterial sample,the magnetic nanoparticles(MNPs)modified with capture antibodies,and the enzymatic probes modified with detection antibodies and glucose oxidase(GOx)were simultaneously injected into the microfluidic chip,followed by mixing and incubation to form MNP-bacteria-probe sandwich ***,glucose with high impedance was injected into the chip and catalyzed by the GOx on the complexes into hydrogen peroxide with high impedance and gluconic acid with low impedance,which was finally measured using the low-cost interdigitated microelectrode and the electrochemical impedance analyzer to determine the target *** the optimal conditions,this biosensor could quantitatively detect *** at the concentrations from 1.6×10^(2) CFU/m L to 1.6×10^(6) CFU/m L in 1 h with the low detection limit of 73 CFU/m ***,this biosensor was demonstrated with good feasibility for practical applications by detecting the *** spiked chicken meat samples.

关键词： Biosensor Microfluidic chip Electrochemical impedance Interdigitated microelectrode Foodborne bacteria

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环形六孔纳米磁珠分离器设计与试验

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农业机械学报 2016年第5期47卷 315-320,335页

作者：刘洪山林杰斯罗锡文莫嘉嗣林建涵焦培荣华南农业大学电子工程学院广州510642 华南农业大学南方农业机械与装备关键技术教育部重点实验室广州510642 华南农业大学工程学院广州510642 华南理工大学机械与汽车工程学院广州510642 中国农业大学教育部现代精细农业系统集成研究重点实验室北京100083 华南农业大学兽医学院广州510642

免疫磁珠分离技术在生物检测中的应用日益广泛,能提供高强度大梯度磁场环境的纳米磁珠分离器是免疫磁珠分离技术中的关键技术之一。设计了一种新颖的环形六孔纳米磁珠分离器,通过瓦状钕铁硼磁块的优化布局和斜壁坡莫合金导磁片设计,实... 详细信息

免疫磁珠分离技术在生物检测中的应用日益广泛,能提供高强度大梯度磁场环境的纳米磁珠分离器是免疫磁珠分离技术中的关键技术之一。设计了一种新颖的环形六孔纳米磁珠分离器,通过瓦状钕铁硼磁块的优化布局和斜壁坡莫合金导磁片设计,实现了在同一台纳米磁珠分离器上形成6个强磁场高梯度分离区域（分离孔）,分离器最高磁场强度达1.44 T,最高磁场梯度达96.3 T/m（体积865.5 cm3,质量4.8 kg）,同一分离器内6个分离孔内磁场分布相同,孔间平均相对偏差在2.0%~3.3%之间。对磁分离孔磁场分布的测试和仿真结果表明：磁珠分离器体积、导磁片材料和导磁片形状等因素对磁珠分离器磁场强度和梯度有不同程度的影响,采用大体积磁块的磁珠分离器比采用小体积磁块的磁珠分离器、采用坡莫合金作为导磁片比采用软铁材料作为导磁片、采用斜壁形状的导磁片比采用直壁形状的导磁片均能实现较大的磁场强度和梯度。该纳米磁珠分离器已成功应用于大肠杆菌和禽流感病毒的免疫磁分离试验研究,并可以根据不同应用需求,组合相关要素以获得理想的免疫磁珠分离器。

关键词：免疫磁分离磁珠分离器磁场分离效率

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面向非规范化数据源的动物体温异常识别方法

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农业机械学报 2023年第11期54卷 295-305页

作者：刘元杰安雯林建涵王雅春刘刚中国农业大学信息与电气工程学院北京100083 中国农业大学动物科学技术学院北京100091

在动物体温异常识别中,红外测温等方式容易产生系统偏差使得判断结果不可靠。基于深度学习的方法在不同测温设备上的鲁棒性与泛化性能较差,且难以应用于数据量少、随机性强、标准不一致等非规范化的测温场景。因此,本文提出了一种面向... 详细信息

在动物体温异常识别中,红外测温等方式容易产生系统偏差使得判断结果不可靠。基于深度学习的方法在不同测温设备上的鲁棒性与泛化性能较差,且难以应用于数据量少、随机性强、标准不一致等非规范化的测温场景。因此,本文提出了一种面向非规范化数据源的动物体温异常识别方法,通过衡量体温时序数据间的相似度即可完成异常识别。针对常用的相似性度量算法在序列匹配、序列间距度量上效果不佳的问题,提出了一种改进的动态时间规整算法(Improved dynamic time warping,iDTW)。在点间度量方式上,综合欧氏距离和一阶导数,改善了序列过度对齐问题。使用序列交并比表示序列整体特征,提升了序列间距度量效果。针对不等长序列及过长序列的异常检测问题,提出了基于滑动窗口和序列等分的异常检测方法。以较短序列为滑动窗口遍历较长序列得到一组序列间距,根据训练和检测的不同阶段分别选择其中的最小值或最大值作为相似度衡量结果,以解决不等长序列匹配问题。将过长的样本数据序列等分为多个子序列,取子序列的间距和为样本间距,以解决过长序列导致的正常样本间距过大和异常漏检问题。在公开数据集UCR上的实验分析表明,相比于欧氏距离、动态时间规整、一阶导数动态时间规整和权重动态时间规整算法,iDTW算法结合K-近邻分类器得到的分类准确率在10个UCR数据集上分别平均提高6.0、3.0、5.2、2.5个百分点。基于滑动窗口和序列等分的异常检测方法相比于经典异常检测算法,在3种动物体温数据集上的F1值均获得了明显提升。

关键词：动物体温异常检测相似性度量动态时间规整非规范化数据源

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An Innovated Laser Control System for Land Leveling Equipment

An Innovated Laser Control System for Land Leveling Equipmen...

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2005北京都市农业工程科技创新与发展国际学术研讨会

作者： Lv Qingfei Liu Gang lin jianhan (Key Laboratory of Modern Precision Agriculture System Integration Research Ministry of Education China Agricultural University)

＜正＞An innovated laser control system for land leveling equipment is discussed in this paper. The system is composed of laser transmitter subsystem for creating a laser plan or laser slopes, a laser receiver that can incept the laser beam and filter the noisy light, and an intelligent controller to identify the signal from receiver and give control signal to the hydraulic system. It’s the key component of laser land leveling system. It is available in the market but its high price is the major obstacle in its extension and application in China. A piece of low-cost laser controlled equipment is studied in this paper. JP3 laser transmitter, a domestic product which can produce rotating 644nm laser, is investigated for land leveling, and a platform which can produce a slope is given out in the paper. When developing the receiver, silicon photoelements are used to detect the relative altitude of the leveling scraper, and the wavelet transform and DSP are used in the equipment. When developing the controller. AT89S51 microprocessor system and embedded control software with fuzzy control rules were developed to process the altitude signals and control the hydraulic system for the leveling scraper. And the cost of laser controlled equipment will be significantly reduced.

关键词： Laser leveling Surface irrigation Wavelet transform

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激光控制平地系统设计与试验分析

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农业机械学报 2006年第1期37卷 71-74页

作者：刘刚林建涵司永胜侯明亮毛恩荣汪懋华中国农业大学现代精细农业系统集成研究教育部重点实验室河北农业大学信息科学与技术学院莱阳农学院工程学院中国农业大学工学院

开发了用于农田平地的激光接收与控制装置、液压调节装置、平地铲等。利用该系统与Trimble公司的激光控制平地系统进行了平地对比试验。试验结果表明,该系统工作性能稳定,与国产中等功率拖拉机液压动力输出匹配较好。

关键词：激光平地机设计试验

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