综述或非传感器论文 2008 非传感器论文

Biosensors and bio-based methods for the separation and detection of foodborne pathogens.

Advances in food and nutrition research Bhunia AK
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Biosensors and bio-based methods for ... 传感器构成示意图

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传感器类型

综述或非传感器论文

检测对象

沙门氏菌(Salmonella,如 S. Typhimurium/S. Enteritidis)、大肠杆菌 O157:H7(E. coli O157:H7)、单核细胞增生李斯特菌(Listeria monocytogenes)、弯曲杆菌(Campylobacter jejuni)、金黄色葡萄球菌肠毒素(SEA/SEB)、真菌毒素(DON、AFB1、FB1、OTA);样品基质:肉/肉制品、奶/乳制品、蔬菜/芽苗、水果、水、粪便/鸡胴体冲洗液、小麦等。

检测原理

综述中的传感方法多基于抗原–抗体、受体–配体或核酸杂交识别。标记型免疫传感器将捕获抗体固定在波导、金膜、石英或电极表面,目标菌/毒素结合后加入荧光或酶标记二抗,形成夹心复合物;荧光标记物被 635 nm 激光激发产生荧光,酶标记物催化底物生成 pH 变化、电化学活性产物或化学发光,信号随目标浓度增加。无标记 SPR/QCM 通过结合质量改变共振波长/角度或晶体频率;阻抗法通过细菌代谢产酸和离子改变电导;细胞法通过病原体裂解细胞释放酶或荧光报告分子。常用放大策略包括免疫磁珠富集、微流控/DEP 捕获、酶催化、FRET 和 PCR 杂交。

检测灵敏度

代表性原文数值:LOD: 0.5 ng/ml;LOD: 1 × 10^3 cfu/ml;LOD: 10^3 cfu/ml;LOD: 1.8 × 10^2 cfu/ml;LOD: 8.7 × 10^6 cfu/ml;LOD: 10^2 cfu/ml;LOD: 10 cells/ml;LOD: 1–10 cfu/ml;LOD: 10–1000 cells/ml;线性范围: 10^5–10^8 cfu/ml;线性范围: 10^2–10^9 cfu/ml;线性范围: 2.5 × 10^5–2.5 × 10^7 cells/crystal;线性范围: 0.13–10 mg/ml;线性范围: 2.5–30 ng/ml;线性范围: 1–10 cfu/ml。

效应效果

综述指出多数平台已在纯培养菌或毒素中验证,真实食品基质验证有限。抗体法选择性高,但多克隆抗体可能交叉反应,单克隆抗体特异性更好;SPR 可实时、无标记、可重复使用,但整菌信号不稳定;光纤传感器可多路检测,SEB 在加标食品中达 0.1 ng/ml,Listeria 在肉样中 1×10^4 cfu/ml 可检出;电化学/化学发光法可在 30–90 min 内检测,E. coli O157:H7 在汉堡中 1 cfu/g 经 6 h 富集可检出;阻抗法可区分活菌并获 AOAC 认可;光散射和 FT-IR 对李斯特菌分类准确率达 90–100% 和 99.2%。作者强调需加强真实样品鲁棒性、样品前处理、成本和自动化。

传感器的构成

  • 换能基底:光学波导(polystyrene optical fiber/glass planar waveguide)、金膜透明波导(SPR gold film)、石英晶体(QCM quartz crystal)或硅芯片(silicon biochip/LAPS),提供光、质量或电学换能基础。
  • 表面修饰层:自组装单分子层(SAM)、羧甲基葡聚糖(CMD)、链霉亲和素(streptavidin)、EDC/NHS 偶联层或 Protein A/G,用于固定抗体、受体或 DNA 探针。
  • 识别元件:单克隆/多克隆抗体(MAb/PAb)、受体分子(acetylcholine receptor、gangliosides GM1/GT1b)或 DNA 探针,用于特异性捕获病原体、毒素或核酸。
  • 信号标记物:Cy5、Alexa Fluor 647 荧光标记抗体,FRET 荧光对(OG-514/QSY-7、Alexa Fluor 546/594),以及 AP、HRP、urease 酶标记抗体,用于产生荧光、电化学或化学发光信号。
  • 底物/电子供体:urea、p-nitrophenyl phosphate(p-NPP)、p-aminophenyl phosphate(p-APP)、1-naphthyl phosphate(1-NP)、luminol、APS-5、menadione,用于酶催化生成可测产物。
  • 富集/前处理元件:免疫磁珠(IMS, Dynabeads)、磁分离器、微流控芯片和介电电泳(DEP)电极,用于从复杂食品基质中捕获和浓缩目标菌。
  • 读出系统:635 nm 激光、CCD/CMOS、光电二极管、石英晶体分析仪、电化学分析仪、光度计/荧光计/化学发光计,用于实时或终点信号采集。

中文摘要

食品安全是消费者、生产者和监管机构长期关注的问题。从农场到餐桌的供应链安全必须得到保障,以防止食源病原体暴发造成严重健康损害。危害分析关键控制点(HACCP)等预防策略需要快速、灵敏、准确的检测工具支持,才能充分发挥作用。传统微生物培养方法虽然可靠,但耗时长、操作繁琐,难以匹配现代食品生产速度和短保质期产品的实时监测需求,也难以自动化。因此,基于生物传感器的检测工具为食源病原体的实时或近实时检测提供了最有希望的方向。本章综述了光学、电化学和质量基生物传感器在食源病原体检测中的应用,并指出生物传感器技术的快速发展也受到食品、水和空气生物恐怖威胁以及政府资助的推动。

英文摘要

The safety of our food supply is always a major concern to consumers, food producers, and regulatory agencies. A safer food supply improves consumer confidence and brings economic stability. The safety of foods from farm-to-fork through the supply chain continuum must be established to protect consumers from debilitating, sometimes fatal episodes of pathogen outbreaks. The implementation of preventive strategies like hazard analysis critical control points (HACCP) assures safety but its full utility will not be realized unless supportive tools are fully developed. Rapid, sensitive, and accurate detection methods are such essential tools that, when integrated with HACCP, will improve safety of products. Traditional microbiological methods are powerful, error-proof, and dependable but these lengthy, cumbersome methods are often ineffective because they are not compatible with the speed at which the products are manufactured and the short shelf life of products. Automation in detection methods is highly desirable, but is not achievable with traditional methods. Therefore, biosensor-based tools offer the most promising solutions and address some of the modern-day needs for fast and sensitive detection of pathogens in real time or near real time. The application of several biosensor tools belonging to the categories of optical, electrochemical, and mass-based tools for detection of foodborne pathogens is reviewed in this chapter. Ironically, geometric growth in biosensor technology is fueled by the imminent threat of bioterrorism through food, water, and air and by the funding through various governmental agencies.

关键词

生物传感器食源病原体免疫传感器表面等离子共振光纤传感器电化学检测