纳米粒子在食源性致病菌检测中的应用进展

食品安全事关人民群众的身体健康和生命安全,而食源性致病菌是食品安全的主要影响因素。由食源性致病菌引起的疾病和死亡持续威胁着全球的公共卫生安全。因此,开发快速、准确且灵敏的食源性致病菌检测方法是预防食源性疾病暴发和确保食品安全的关键。常规检测方法费时费力,需要昂贵的设备和专业的人员,应用受限。近年来,随着纳米技术的快速发展,纳米粒子凭借其小尺寸、高比表面积和高反应活性等理化特性成为食源性致病菌检测领域的研究热点。此外,将识别元件修饰于纳米粒子表面并结合新颖的分析技术,能提高检测的特异性和灵敏度。该综述主要总结和比较了磁性纳米粒子、贵金属纳米粒子、荧光纳米粒子和二氧化硅纳米粒子在食源性致病菌检测中的应用,以期为食源性致病菌的快速分析提供思路。     

基于识别分子的磁分离技术在食源性致病菌分离中应用

食源性致病菌是一类对人类健康危害极大的致病菌,但由于其在食品基质中数量较少,通常需要在检测前对其进行富集。磁分离作为一种常用的前处理手段,在致病菌的富集、分离方面展示出极好的应用前景。常用于修饰在磁性材料上的识别分子有多种,本文主要综述了抗体、抗生素、核酸、凝集素等主要的几种识别分子在磁分离中的应用。     

基于识别分子的磁分离技术在食源性致病菌分离中应用

食源性致病菌是一类对人类健康危害极大的致病菌,但由于其在食品基质中数量较少,通常需要在检测前对其进行富集。磁分离作为一种常用的前处理手段,在致病菌的富集、分离方面展示出极好的应用前景。常用于修饰在磁性材料上的识别分子有多种,本文主要综述了抗体、抗生素、核酸、凝集素等主要的几种识别分子在磁分离中的应用。     

食源性致病菌快速检测方法研究进展

食源性致病菌污染是导致食品安全问题的重要因素,食源性致病菌的检测已成为近年来研究的热点.以免疫分析、分子生物学、生物传感器、代谢组学、核酸适配体等技术为基础的快速检测方法发展迅速,已成为检测食源性致病菌的主要方法.该文结合近年来各种快速检测方法的相关研究进展,介绍了以上述技术为基础的快速检测食源性致病菌的方法,并讨论了...     

万古霉素修饰磁性纳米粒子的制备及其细菌分离功能

制备了万古霉素修饰的磁性纳米粒子, 并研究了其对金黄色葡萄球菌(S.aureus)和大肠杆菌(E.coli BL21)的选择性吸附分离特性.     

检测大肠杆菌的免疫生物传感器研究进展

大肠杆菌是人体内常见的食源性致病菌,对其检测极为重要。免疫生物传感器技术作为目前研究较热的一种技术,在大肠杆菌的检测方面有不错的进展。本文综述了电化学、光学、压电等类型免疫传感器近十年的研究进展,从检测原理、抗体固定方式、修饰材料、检测能力等方面进行了综述,并对各自的优劣势进行了讨论,对免疫传感器的发展趋势进行了总结与展望。     

表面增强拉曼光谱技术在快速、灵敏检测食源性致病菌中的应用

食源性致病菌的快速、灵敏检测是食品和药品安全领域关注的重点.表面增强拉曼光谱(SERS)技术凭借其检测速度快、信息丰富、灵敏度高、无损等优势在食源性致病菌的快速、灵敏检测中受到广泛关注.本文从SERS检测基底材料入手,综述了液相基底、刚性固相基底、柔性固相基底等材料的特点和性能,并对其在致病菌快速、灵敏检测中的应用进行...     

应用傅里叶变换红外光谱区分鉴定四种食源性致病菌的研究

利用傅里叶变换红外光谱技术(FT-IR)对大肠杆菌O157: H7、肠炎沙门氏菌、单核增生性李斯特菌、金黄色葡萄球菌这四种典型食源性致病菌进行了研究. 对其红外谱图进行基线校正和归一化处理, 对其谱带归属进行判别分析, 选取具有菌株特性的1500～800 cm^－1的谱带, 进行一阶导数运算, 结合化学计量学方法主成分分析(PCA)和聚类分析(CA), 并进行相关系数的统计学分析, 得出以下结果: 四种食源性致病菌最大相关系数为0.937, 最小相关系数为0.058, 而且四种不同的细菌在PCA和CA分析图上也达到了很好的区分效果. 研究表明, FT-IR有望成为一种快速检测食源性致病菌的新方法.     

食源性致病菌现场即时检测技术研究进展

食源性致病菌如大肠杆菌、沙门氏菌、金黄色葡萄球菌等是食源性疾病和食物中毒的主要原因,通常污染水果、蔬菜、肉类和海鲜,严重威胁食品安全。食源性致病菌的快速检测对公共卫生和食品安全至关重要。然而,传统的检测方法繁琐耗时,难以满足快检快诊的需求。现场即时检测(POCT)技术作为一种新兴的现场快速检测分析技术,具有操作简单、快速、便携式和自动化等优点。POCT技术作为近年来发展迅速的食源性病原菌检测方法,为低成本、高灵敏度和高特异性检测食源性病原体提供了一种新途径。目前,POCT使用的技术主要包括光学技术和生物传感器技术,主要基于免疫学反应和生化反应。本文综述了近年来基于比色、纸基、微流控、电磁传感及市售便携式读数平台的POCT技术在食源性致病菌检测中的应用研究现状,并展望了其未来的发展前景和方向。     

聚乙二醇-金纳米棒介导的近红外光热抑菌作用

种子生长法合成纵向表面等离子体共振吸收峰为785 nm的金纳米棒,并对其表面进行聚乙二醇(PEG)修饰,研究了表面修饰PEG的金纳米棒(polyethylene glycol modified gold nanorods,PEG-GNR)的光热转化效应,并测试了其细胞毒性。以革兰氏阳性菌金黄色葡萄球菌、蜡状芽孢杆菌,革兰氏阴性菌大肠埃希氏菌及铜绿假单胞菌为细菌模型,详细研究了PEG-GNR在808nm波长近红外激光照射下金纳米棒浓度和照射功率对抑菌效果的影响。结果表明,PEG-GNR对革兰氏阳性菌和革兰氏阴性菌在近红外照射下均有较好的抑菌效果,并且抑菌效果与金纳米棒的浓度和照射功率有着密切的关系;结合荧光显微镜和透射电子显微镜对细菌坏死状况的观察,初步证实细菌对PEG-GNR有效吸收是近红外光热杀菌的关键因素。     

A magnetic Gram stain for bacterial detection

Magnetizing: Bacteria are often classified into gram-positive and gram-negative strains by staining with crystal violet (CV). The described bioorthogonal modification of CV with trans-cyclooctene (TCO) can be used to render gram-positive bacteria magnetic with tetrazine-functionalized magnetic nanoparticles (MNP-Tz). This method allows class-specific automated magnetic detection and magnetic separation.     

Specific detection of Campylobacter jejuni using the bacteriophage NCTC 12673 receptor binding protein as a probe

Campylobacter jejuni is found in the intestines of poultry, cattle, swine, wild birds and pet animals and is the major cause of foodborne gastroenteritis in developed countries. We report the use of the receptor binding protein (RBP) of Campylobacter bacteriophage NCTC 12673 for the specific capture of Campylobacter jejuni bacteria using RBP-derivatized capturing surfaces. The Gp48 RBP was expressed as a glutathione S-transferase-Gp48 (GST-Gp48) fusion protein and immobilized onto surface plasmon resonance (SPR) surfaces using glutathione self-assembled monolayers (GSH SAM). Bovine serum albumin (BSA) was used to block any non-specific binding. Glutathione SAM leads to an oriented attachment of the protein, resulting in a two- to three-fold improvement of bacterial capture when compared to dithiobis(succinimidyl propionate) (DTSP) SAM-based unoriented attachment. The specificity of recognition was confirmed using Salmonella enterica subsp. enterica serovar Typhimurium as a negative control, which indeed showed negligible binding. The detection limit of the RBP-derivatized SPR surfaces was found to be 10(2) cfu/ml. Finally, GST-Gp48 was also immobilized onto magnetic beads that were successfully used to capture and pre-concentrate the host pathogen from suspension.     

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

Screening of foodborne pathogens is important to prevent contaminated foods from their supply chains. In this study, a portable detection device was developed for rapid, sensitive and simple detection of viable Salmonella 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 extraction 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 and analyzed using a self-developed smartphone App to quantitatively determine the bacterial concentration. This device could detect Salmonella typhimurium in spiked chicken meats from 1.3 × 10² CFU/mL to 1.3 × 10⁷ CFU/mL in 2 h with a lower detection limit of 130 CFU/mL, and has shown its potential for on-site detection of foodborne pathogens.     

Magnetorheological elastomer and smartphone enable microfluidic biosensing of foodborne pathogen

Rapid detection of foodborne pathogens is crucial to prevent the outbreaks of foodborne diseases. In this work, we proposed a novel microfluidic biosensor based on magnetorheological elastomer (MRE) and smartphone. First, micropump and microvalves were constructed by deforming the MRE under magnetic actuation and integrated into the microfluidic biosensor for fluidic control. Then, 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 complexes. After 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 bacteria. Under optimal conditions, this biosensor could detect Salmonella typhimurium quantitatively and automatically in 1 h with a linear detection range of 8.0 × 10¹ CFU/mL to 8.0 × 10⁴ CFU/mL and a detection limit of 62 CFU/mL. The 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.     

基于金属有机骨架材料的生物传感器在食源性致病菌或毒素检测中的应用

食源性致病菌或其产生的毒素污染的食物会给人体健康带来严重威胁,并造成巨大的经济损失。近年来,金属有机骨架材料(MOFs)作为一种新型的多孔晶体材料,因其具有大的表面积、高的孔隙率等特点,受到人们的广泛关注。将MOFs与生物传感器结合用于食源性致病菌或毒素的检测引起了研究者的兴趣。基于此,本文介绍了MOFs用于生物传感器的优势,概述了MOFs在不同的电化学和光学生物传感器的应用,综述了基于MOFs的生物传感器在致病菌或毒素的研究进展,讨论了基于MOFs的生物传感器在致病菌或毒素所面临的挑战和展望。     

食源性致病菌的表面增强拉曼光谱检测技术研究进展

食源性致病菌引起的疾病的快速管控与预防是当前各国面临的食品安全监管难题之一,受到社会各界的广泛关注.目前常用的食源性致病菌检测方法存在步骤复杂、耗时、灵敏度低或选择性差等局限,发展快速、可靠的食源性致病菌检测方法仍是食品安全和公众健康的热点研究领域.表面增强拉曼光谱(SERS)作为一种新型的光谱快检技术,具有灵敏度高、...     

Simultaneous detection of Escherichia coli O157:H7 and Salmonella Typhimurium using quantum dots as fluorescence labels

In this study, we explored the use of semiconductor quantum dots (QDs) as fluorescence labels in immunoassays for simultaneous detection of two species of foodborne pathogenic bacteria, Escherichia coli O157:H7 and Salmonella Typhimurium. QDs with different sizes can be excited with a single wavelength of light, resulting in different emission peaks that can be measured simultaneously. Highly fluorescent semiconductor quantum dots with different emission wavelengths (525 nm and 705 nm) were conjugated to anti-E. coli O157 and anti-Salmonella antibodies, respectively. Target bacteria were separated from samples by using specific antibody coated magnetic beads. The bead-cell complexes reacted with QD-antibody conjugates to form bead-cell-QD complexes. Fluorescent microscopic images of QD labeled E. coli and Salmonella cells demonstrated that QD-antibody conjugates could evenly and completely attach to the surface of bacterial cells, indicating that the conjugated QD molecules still retain their effective fluorescence, while the conjugated antibody molecules remain active and are able to recognize their specific target bacteria in a complex mixture. The intensities of fluorescence emission peaks at 525 nm and 705 nm of the final complexes were measured for quantitative detection of E. coli O157:H7 and S. Typhimurium simultaneously. The fluorescence intensity (FI) as a function of cell number (N) was found for Salmonella and E. coli, respectively. The regression models can be expressed as: FI = 60.6 log N- 250.9 with R(2) = 0.97 for S. Typhimurium, and FI = 77.8 log N- 245.2 with R(2) = 0.91 for E. coli O157:H7 in the range of cell numbers from 10(4) to 10(7) cfu ml(-1). The detection limit of this method was 10(4) cfu ml(-1). The detection could be completed within 2 hours. The principle of this method could be extended to detect multiple species of bacteria (3-4 species) simultaneously, depending on the availability of each type of QD-antibody conjugates with a unique emission peak and the antibody coated magnetic beads specific to each species of bacteria.     

基于抗菌肽的生物传感器在食源性致病菌检测中的应用

快速检测食源性致病菌是预防食源性疾病大量暴发的必要措施。基于生物传感器的食源性病原菌检测技术具有灵敏度高、实时定量、操作简便等优点。抗菌肽(antimicrobial peptides,AMPs)作为识别分子具有稳定性高和成本低的特点,在食源性致病菌的快速检测中得到了广泛的应用。将抗菌肽与生物传感器结合用于食源性致病菌具有潜在的实际应用价值。本文综述了基于抗菌肽的电化学方法和光学方法在食源性致病菌检测的应用,讨论了基于抗菌肽的高灵敏度和可靠检测平台的未来前景和挑战。