农产品/食品中农药残留快速检测方法研究进展

农药残留的识别和量化通常依赖于气相色谱法、高效液相色谱法、气/液相色谱-质谱联用法以及毛细管电泳法,这些方法需涉及大而贵重的仪器、费时的样品处理以及专门的技术培训。因此,建立在线、高灵敏度、高选择性、简单高效、低成本的农药残留快速检测方法和技术非常重要。该文综述了用于农产品/食品的农药残留分析快速检测方法,主要包括酶抑制法、免疫分析法、光谱法(包括可见/近红外、红外、拉曼和激光诱导击穿光谱等)以及各种生物传感器等,分别介绍了这些方法最新的研究进展,同时分析并总结了这些快速检测方法和技术的基本原理和特点。目前的研究在灵敏度、重复性、准确性方面存在着一些不足,商品化的农药残留检测仪器也比较单一。由于纳米生物技术、分子印迹技术和微流控技术等技术有着巨大的应用潜力,因此特别介绍了这些技术在农药残留分析中的应用。农药残留快速分析技术未来将会朝着检测仪器的小型化和集成化、多通道检测、无线通讯方向发展,提高快速检测方法和仪器的稳定性和可靠性是必然趋势。     

生物传感器在农药残留检测中的应用

农药的广泛使用需要可靠的工具对其进行监测，从而保护人类和环境安全。传统的分析方法由于繁琐耗时或仪器的昂贵有其局限性。生物传感器是一种以生物活性单元为敏感元件，结合化学、物理转换元件，对被分析物具有高度选择性的仪器，可以用来检测农药残留等污染物。该文综述了近年来生物传感器在环境、食品和农产品农药残留检测中的研究进展。     

畜禽产品中兽用抗生素残留检测技术研究

抗生素残留造成的环境污染及食品安全问题已成为目前研究的热点。本文介绍了畜禽产品中兽用抗生素检测的前处理方法,包括传统前处理方法、分散固相萃取技术、固相萃取技术等,分析了当前畜禽产品中兽用抗生素残留检测技术研究进展及应用,并提出了未来研究发展方向。     

生物传感器在水产品新鲜度检测中的应用与研究进展

新鲜度是判断水产品品质的一项重要指标。传统新鲜度检测方法大多繁琐、费时费力,建立快速便捷的检测方法具有重要的现实意义和学术价值。生物传感器操作简单、检测快速、成本低,近年来被广泛研究应用于水产品新鲜度的检测。本文在简要阐述传统和新型新鲜度检测方法的基础上,综述了生物传感器在水产品新鲜度检测上的应用,着重介绍了酶固定载体和纳米传感器方面的最新进展,并概述用于水产品新鲜度检测的生物传感器技术当前存在的问题及发展趋势,旨在为该光传感器的后续研发提供参考。     

微生物细胞传感器在环境监测中的应用研究进展

微生物细胞传感器是以微生物细胞作为生物敏感元件,可以感应环境中的总毒性以及各类污染物,从而实现快速监测的目的。关于该领域的研究报道越来越多,随着研究的不断发展,该项技术日趋成熟,从开始的仅仅在环境总毒性监测方面的应用,发展到能够特异性地检测多种污染物,如重金属类(Hg、Cd、As、Pb、Cu、Ag、Ni等)、有机污染物类(苯系物质、PAHs、酚类物质等)、抗生素类(四环素、β-内酰胺等)以及N、P类营养元素等等。由于微生物细胞自身的一些特点,使得其在环境监测领域具有非常显著的特点和优势,特别是在检测污染物的生物有效性方面,同时该技术可以满足环境监测中原位、快速、低耗的需要,所以其在环境监测领域必将得到越来越广泛的应用。本文重点综述了微生物细胞传感器在环境监测中的一些应用研究进展,并展望了其未来的发展趋势。     

检测有机磷农药残留生物传感器的温度特性

为了考察检测有机磷农药残留用量热式生物传感器的温度特性，本文采用分光光度法研究了固定化鸡肝酯酶的活力、农药敌敌畏对鸡肝酯酶的抑制等与温度的关系。在生物传感器的实测条件下，研究了不同温度固定化酶活力的操作流失情况。研究显示，温度对酶反应的影响很大，控温精度的提高将增强检测的精度和稳定性。温度55～60℃时，是酶反应速度最快的区域；抑制时间5 min时，农药敌敌畏对鸡肝脂酶产生了明显的抑制作用。在农药浓度小于1 mg/L的区域，随浓度变化的相对抑制关系接近于线性；一定浓度的农药敌敌畏对酶的抑制程度随着温度的变     

检测食品沙门氏菌的生物传感器持久性研究

为了研究温度对生物传感器检测的持久性的影响,制备了用于检测食品中沙门氏菌的磁致伸缩生物传感器,以磁致伸缩膜片作为物理传感器,多克隆抗体作为生物识别元件,采用Langmuir-Blodgett(LB)技术将多克隆抗体固定在磁致伸缩膜片表面。当食品中沙门氏菌吸附在生物传感器上时,将引起其共振频率漂移。通过测试与分析磁致伸缩生物传感器共振频率漂移值,并利用扫描电子显微镜(scanning electron microscope)观察吸附了沙门氏菌的生物传感器表面,对生物传感器在25(室温)、45及65℃的持久性进行研究。结果表明:多克隆抗体磁致伸缩生物传感器与沙门氏菌的结合能力随着时间的延长逐渐降低;且温度越高,传感器的持久性越差;在25、45及65℃时,多克隆抗体磁致伸缩生物传感器的持久期分别为30、8和5 d,由此获得了多克隆抗体生物传感器在常用温度下的持久性。并结合阿伦尼乌斯方程,计算得到该生物传感器的激活能为13.024 kJ/mol。进一步证实了磁致伸缩生物传感器可用于定量检测实际溶液中沙门氏菌的浓度,表明生物传感器可应用于食品中细菌的实时快速定量检测。     

生物监测在水环境污染监测中的现状与展望

本文介绍了水质生物监测的定义、原理及其特点和主要方法:生物群落法、细菌学检验法、水生生物毒性试验、生产力测定法、微型生物监测、分子生态毒理学方法、硝化细菌测试法、幼虫变态实验、发光细菌毒性检测法、生物传感器、DNA生物传感器、聚合酶链反应技术,展望了生物监测的应用前景。     

磁致伸缩生物传感器尺寸对沙门氏菌检测灵敏度的影响

为了研究不同尺寸传感器的检测灵敏度,该文以磁致伸缩膜片为物理传感器,多克隆抗体为生物识别元件,采用Langmuir-Blodgett(LB)技术将多克隆抗体固定在磁致伸缩膜片表面,制备了用于检测沙门氏菌的磁致伸缩生物传感器。检测时,将不同尺寸的生物传感器浸在含有沙门氏菌的被测溶液里,由于生物传感器对沙门氏菌的吸附使传感器质量增加,从而使传感器共振频率发生改变。采用尺寸为2 mm×0.4 mm×15μm,5 mm×1 mm×15μm和25 mm×5 mm×15μm的传感器检测浓度为102~109 CFU/m L的沙门氏菌溶液,并利用扫描电子显微镜观察传感器表面。研究结果表明,由传感器共振频率变化计算获得的沙门氏菌浓度与扫描电子显微镜观察统计分析获得的直观浓度吻合得很好,两者最大相对差值小于10%。传感器尺寸越小,检测灵敏度越高。尺寸为2 mm×0.4 mm×15μm,5 mm×1 mm×15μm和25 mm×5 mm×15μm的检测极限分别为5×103 CFU/m L,105 CFU/m L和107 CFU/m L。研究结果可为磁致伸缩生物传感器实际应用时,根据预测的细菌浓度,在保证灵敏度的前提下选择合适尺寸的传感器提供参考。     

DNA调控金纳米探针及其在食品安全检测的应用

近年，食品安全问题逐渐受到重视，食品安全检测方法除了常用的简单化学分析、仪器分析，还发展出一些新兴检测方法如纸基微型分析系统等，但均有一定局限性。本研究综述了DNA介导的金纳米材料在食品安全检测领域的研究进展，DNA作为一种覆盖剂，被应用于介导金属纳米粒子种子形态的转变和性能的增强，其中金纳米性质最为优良；介绍了其形成机制，系统地总结了由物理吸附和硫代DNA介导的具有不同形态的金纳米材料，并介绍了这些材料的稳定性、识别特性、光学特性、催化特性、生物相容性及其生物传感应用。本研究为DNA介导的纳米材料的生长及其在生物传感等领域的应用奠定了基础。     

The application of biosensors to fresh produce and the wider food industry

The inherent specificity, selectivity, and adaptability of biosensors make them ideal candidates for use throughout the food industry. Potential applications within the supply chain range from testing of foodstuffs for maximum pesticide residue verification through to the routine analysis of analyte(s) concentrations, such as, glucose, sucrose, alcohol, etc., which may be indicators of food quality/acceptability. Biosensor formats include simple "one-shot" disposable devices that can be used either in the field or integrated into more sophisticated laboratory instruments. Until now, the main impact of these devices has been in the medical diagnostics field. However, with ongoing technical development, the food industry will be one of the prime beneficiaries of biosensor technology in the future. This report assesses the current and future trends in the application of biosensors to fresh produce and the wider food industry, focusing on both potential and current target analytes that are fundamental to fresh produce quality, traceability, and safety.     

Biosensor Technology addressing Agricultural Problems

Biosensor technology is a powerful alternative to conventional analytical techniques, harnessing the specificity and sensitivity of biological systems in small, low cost devices. Despite the promising biosensors developed in research laboratories, there are not many reports of applications in agricultural monitoring. The authors review biosensor technology and discuss the different bio-receptor systems and methods of transduction. The difference between a biosensor and a truly integrated biosensor system are defined and the main reasons for the slow technology transfer of biosensors to the marketplace are reported. Biosensor research and development has been directed mainly towards health care, environmental applications and the food industry. The most commercially important application is the hand-held glucose meter used by diabetics. The agricultural/veterinary testing market has seen a number of diagnostic tests but no true biosensor systems have made an impact. The need for fast, on-line and accurate sensing opens up opportunities for biosensors in many different agricultural areas —in situ analysis of pollutants in crops and soils, detection and identification of infectious diseases in crops and livestock, on-line measurements of important food processing parameters, monitoring animal fertility and screening therapeutic drugs in veterinary testing. Future challenges in the commercial development of biosensor are also addressed.     

Irrigation,a productive tool for food security – a review

Water scarcity in agriculture is becoming a major problem due to increasing demand from nonagricultural uses and intensive crop management on existing croplands to meet the needs of an expanding global population. Efficient use of the available irrigation water is therefore of important concern. Even though intensive research in the areas of crop physiology, irrigation engineering, agronomy and agricultural economics has developed several ways to improve the efficiency of irrigation water, a multidisciplinary approach is often regarded as the best future path to achieve further enhancements in meeting the forthcoming challenge of producing more and safety foods. Failure of irrigation production has profound effects on the welfare of all those employed in it and also their customers. Indeed, the scale of the industry is such that world food prices will be influenced by the overall performance of the irrigation farmers, but low food prices are essential to the welfare of the poorest people. The contribution of irrigation and water management to increased food production must come through both expansion of irrigation and improved management of existing water supplies. This review presents the past, current and future panorama of irrigation as a viable tool in ensuring food security on the globe. Considering past trends, this review empathizes that future irrigation technologies should be focused on providing the leadership and capacity to capture, develop and promote new irrigation practices and management systems to optimize production.     

Effect of processing on recovery and variability associated with immunochemical analytical methods for multiple allergens in a single matrix: sugar cookies

Among the major food allergies, peanut, egg, and milk are the most common. The immunochemical detection of food allergens depends on various factors, such as the food matrix and processing method, which can affect allergen conformation and extractability. This study aimed to (1) develop matrix-specific incurred reference materials for allergen testing, (2) determine whether multiple allergens in the same model food can be simultaneously detected, and (3) establish the effect of processing on reference material stability and allergen detection. Defatted peanut flour, whole egg powder, and spray-dried milk were added to cookie dough at seven incurred levels before baking. Allergens were measured using five commercial enzyme-linked immunosorbent assay (ELISA) kits. All kits showed decreased recovery of all allergens after baking. Analytical coefficients of variation for most kits increased with baking time, but decreased with incurred allergen level. Thus, food processing negatively affects the recovery and variability of peanut, egg, and milk detection in a sugar cookie matrix when using immunochemical methods.     

食品电物性在无损检测中的应用研究进展

现代农业和食品加工的快速发展，使农产品的品质检测技术显得非常重要。无损检测技术已成为食品科学的一个重要研究热点，利用电物性对农产品品质检测、分级筛选等方面已显示出特殊的优越性。该文从农产品的含水量、可溶性固形物含量、新鲜程度等指标的检测及食品干燥、油炸、发酵、冷冻等过程的在线检测方面，阐述了利用电物性的食品无损检测技术的研究现状，也提出了今后进一步研究的方向和目标。     

Strengthening Analytical Support in Agricultural Research

The need for analytical support in agricultural research and development has long been recognized, especially for soil fertility evaluation and management, assessment of crop and food quality, and selection and breeding of nutritious food staples. In addition, the demand for analytical research support in the general areas of agriculture interfacing with human health and environmental quality has greatly increased in recent years. The trend for increased demand for analytical support will most likely continue in the future. To meet such diverse, increasing demands for analytical support, we need to upgrade infrastructure facilities and simultaneously teach and train students and young researchers in the use of modern analytical tools. This is prerequisite to providing timely, efficient, and effective analytical support, as such support is the key to monitoring, assessing, and maintaining soil, food, and environmental quality and to breeding nutritious food staples.     

Immunoassays and biosensors for monitoring environmental and human exposure to pyrethroid insecticides

This paper describes some of the early work on pyrethroid insecticides in the Casida laboratory and briefly reviews the development and application of immunochemical approaches for the detection of pyrethroid insecticides and their metabolites for monitoring environmental and human exposure. Multiple technologies can be combined to enhance the sensitivity and speed of immunochemical analysis. The pyrethroid assays are used to illustrate the use of some of these immunoreagents such as antibodies, competitive mimics, and novel binding agents such as phage-displayed peptides. The paper also illustrates reporters such as fluorescent dyes, chemiluminescent compounds, and luminescent lanthanide nanoparticles, as well as the application of magnetic separation, and automatic instrumental systems, biosensors, and novel immunological technologies. These new technologies alone and in combination result in an improved ability to both determine if effective levels of pyrethroids are being used in the field and evaluate possible contamination.