生物传感器在食源性致病菌检测中应用的研究进展

食源性致病菌作为引起食源性疾病的主要因素,受到人们的高度重视,发展简便、快速、高灵敏度和低成本的食源性致病菌检测方法对降低食源性疾病发病率具有重要意义。生物传感器技术是一种由多学科交叉渗透发展形成的全新微量分析技术,具有灵敏度高、分析速度快等特点,被广泛应用于食源性致病菌的检测。文中介绍了生物传感器的基本原理,综述了常见的生物传感器在食源性致病菌检测中的应用,并对其发展趋势进行了展望。     

Electrochemiluminescent functional nucleic acids‐based sensors for food analysis

Foodborne contaminants widely exist in foods, which can lead to various foodborne diseases and food safety issues. The development of quick, sensitive and universal analytical approaches for foodborne contaminants is imperative. Electrochemiluminescent functional nucleic acids (ECL FNAs)‐based sensors are a series of sensing devices using FNAs as the recognition elements and ECL as the transducer. Contributing to the specific recognition ability of FNA and the high sensitivity of ECL, ECL FNA‐based sensors are considered to be of great application potential for foodborne contaminants monitoring. This review mainly presents the applications of ECL FNA‐based sensors for foodborne contaminants (including microorganisms, mycotoxins, allergens, antibiotics, heavy metal ions, pesticides and some illegal additives). In general, the application of ECL FNA‐based sensors in the field of food analysis is just in its infancy. Although there are several limitations and challenges, it is envisaged that ECL FNA‐based sensors will have broad prospects for food analysis in the future.     

食源性致病菌检测免疫传感器研究进展

食源性致病菌是造成食品安全事件的主要原因之一,因此其检测方法已成为人们研究的热点.食源性致病菌的检测方法主要有病原体培养法、免疫学方法、核酸检测和生物传感器等.其中,免疫传感器基于抗原抗体特异性结合,整合光学、电化学等多学科交叉技术,具有特异性强、检测速度快等特点.本文对比食源性致病菌传统检测方法,综述了近年来免疫传感...     

An integrated biosensor platform for extraction and detection of nucleic acids

The development of portable systems for analysis of nucleic acids (NAs) is crucial for the evolution of biosensing in the context of future healthcare technologies. The integration of NA extraction, purification, and detection modules, properly actuated by microfluidics technologies, is a key point for the development of portable diagnostic systems. In this paper, we describe an integrated biosensor platform based on a silicon–plastic hybrid lab-on-disk technology capable of managing NA extraction, purification, and detection processes in an integrated format. The sample preparation process is performed by solid-phase extraction technology using magnetic beads on a plastic disk, while detection is done through quantitative real-time polymerase chain reaction (qRT-PCR) on a miniaturized silicon device. The movement of sample and reagents is actuated by a centrifugal force induced by a disk actuator instrument. The assessment of the NA extraction and detection performance has been carried out by using hepatitis B virus (HBV) DNA genome as a biological target. The quantification of the qRT-PCR chip in the hybrid disk showed an improvement in sensitivity with respect to the qRT-PCR commercial platforms, which means an optimization of time and cost. Limit of detection and limit of quantification values of about 8 cps/reaction and 26 cps/reaction, respectively, were found by using analytical samples (synthetic clone), while the results with real samples (serum with spiked HBV genome) indicate that the system performs as well as the standard methods.     

核酸定量检测方法研究进展

核酸相关的研究和应用广泛存在于各个学科领域,与之相关的核酸定量检测技术越来越受到研究人员的重视。本文对目前实验室广泛采用的和近几年进展迅速的核酸定量方法(包括紫外分光光度法、荧光染料法、实时荧光定量PCR法、数字PCR法等)进行介绍,着重阐述其检测原理和优缺点,为研究人员今后进行相关研究提供参考。     

食源性致病菌激活NLRP3炎症小体及食源性功能物质的抑制机理研究进展

食源性致病菌感染是引起食源性疾病的首要因素,严重影响人类健康。炎症小体通过识别受体感知入侵宿主的危险信号进而组装形成多聚蛋白复合物,从而诱导炎症反应,是先天免疫系统中识别食源性病原菌感染和清除病原体的重要防线。NLRP3炎症小体是位于胞内的炎症反应平台,可以感知多种病原微生物的侵袭,在先天性免疫反应中起着至关重要的作用。食源性致病菌感染常引起NLRP3炎症小体的异常激活,介导多种炎症性疾病的发生和发展,因此,许多抗炎研究中常常以NLRP3炎症小体作为靶点。本文总结了食源性致病菌及其代谢产物激活NLRP3炎症小体的分子机制,以及天然产物和膳食功能物质抑制NLRP3炎症小体激活的机理,为治疗炎症性疾病、开发缓解致病菌诱导的炎症反应的功能化合物提供新的思路。     

基于CRISPR/Cas技术的核酸检测研究进展

由成簇、规则间隔的短回文重复序列（Clustered regularly interspaced short palindromic repeats,CRISPR）和CRISPR相关蛋白（CRISPR-associated protein,Cas）组成的CRISPR/Cas系统是广泛存在于多数细菌和古细菌中的一种适应性免疫系统。CRISPR/Cas系统可识别并结合外源入侵的核酸分子,之后Cas蛋白的切割活性被激活,能够对入侵的核酸分子进行切割使其降解。利用CRISPR/Cas系统特异的序列识别及切割活性,将其应用于核酸检测中,为提高检测灵敏度及特异性等性能指标提供了一种新思路。本文介绍了CRISPR/Cas系统的发展、作用机制等,对多样化的Cas蛋白在核酸检测中的代表性应用研究进行总结,进一步讨论了CRISPR/Cas技术应用于核酸检测中存在的优缺点,并对未来研究进行了展望,为基于CRISPR/Cas技术的核酸检测方法在病原微生物的检测中提供参考和依据。     

无胶筛分毛细管电泳中核酸的迁移行为及分离的研究

无胶筛分毛细管电泳分析小于1kb的核酸,其迁移率与碱基数的对数成线性关系,长度大于1kb核酸的迁移率不是仅由其分子大小决定。据此可推测小于1kb核酸片段的大小。采用不更换聚合物法分析核酸,迁移时间的变异系数小于1.3％,适于大量样本的快速测定。考虑温度对核酸迁移行为的影响时,观察到22℃时,柱效最高。电进样与压力进样相比,分析大于300bp核酸的柱效提高,但不适于定量分析。     

鞘翅目昆虫核酸分子系统学研究现状

从研究对象、研究种类、研究内容等方面对鞘翅目Coleoptera核酸分子系统学研究的近况进行了总结和分析,研究中应用的技术主要有DNA序列分析、RELP技术、RAPD技术、AFLP技术、分子杂交技术和SSCD技术。并认为这些技术的应用对补充和完善传统分类方法,深入探讨各类群的分类地位和系统发育关系具有重要作用。     

光纤生物传感器及其在微生物检测中的应用

本文介绍了光纤生物传感器的原理,对光纤传感器制作中的工程学和生物学问题进行了探讨并概述了它的应用情况。     

Novel nucleic acid detection strategies based on CRISPR-Cas systems: From construction to application

Beyond their widespread application as genome-editing and regulatory tools, clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) systems also play a critical role in nucleic acid detection due to their high sensitivity and specificity. Recently developed Cas family effectors have opened the door to the development of new strategies for detecting different types of nucleic acids for a variety of purposes. Precise and efficient nucleic acid detection using CRISPR-Cas systems has the potential to advance both basic and applied biological research. In this review, we summarize the CRISPR-Cas systems used for the recognition and detection of specific nucleic acids for different purposes, including the detection of genomic DNA, nongenomic DNA, RNA, and pathogenic microbe genomes. Current challenges and further applications of CRISPR-based detection methods will be discussed according to the most recent developments.     

Impact of molecular biology on the detection of foodborne pathogens

Molecular biological methods that use antibodies and nucleic acids to detect specific foodborne bacterial pathogens were scarcely known a decade and a half ago. Few scientists could have predicted that these tools of basic research would come to dominate the field of food diagnostics. Today, a large number of cleverly designed assay formats using these technologies are available commercially for the detection in foods of practically all major established pathogens and toxins, as well as of many emerging pathogens. These tests range from very simple antibody-bound latex agglutination assays to very sophisticated DNA amplification methods. Although molecular biological assays are more specific, sensitive, and faster than conventional (often cultural) microbiological methods, the complexities of food matrices continue to offer unique challenges that may preclude the direct application of these molecular biological methods. Consequently, a short cultural enrichment period is still required for food samples prior to analysis with these assays. The greater detection sensitivity of molecular biological methods may also affect existing microbiological specifications for foods; this undoubtedly will have repercussions on the regulatory agencies, food manufacturers, and also consumers. The US government has the right to retain a nonexclusive royalty-free license in and to any copyright covering this article. Use of trade names is for identification only and does not imply an endorsement by the US FDA.     

Peptide nucleic acids and the origin of life

The possibilities of pseudo-peptide-DNA mimics like PNA (peptide nucleic acid) having a role for the prebiotic origin of life prior to an RNA world is discussed on the basis of literature data showing that this type of molecules might have formed on the primitive earth (or other places in the universe), as well as data indicating the possibilities of template-directed PNA chemical replication and ligation. In particular, the merits of an achiral prebiotic genetic material is discussed.     

A comparison of two autoradiographic methods for detecting radiolabeled nucleic acids in embryos.

Two methods for preparing embryos for autoradiographic study of newly synthesized nucleic acids are described and compared. The first method consists of rapidly fixing radiolabeled embryos with acetic acid:methanol, spreading them on glass slides and exposing them for 8 days with a photographic emulsion. The second method consists of fixing, embedding in resin, and sectioning the embryos before their exposure with the emulsion for 3 weeks. Both techniques have many applications in studies of early embryonic activity, but the spread technique is very sensitive, simpler, and faster.     

Electrophoresis of proteins and nucleic acids on acrylamide-agarose gels lacking covalent crosslinking

The preparation of acrylamide-agarose gels lacking covalent crosslinking with methylenebisacrylamide is described. These hybrid gels melt at 85 degrees C and, consequently, allow quantitative analysis of tritium-labeled protein after electrophoresis. Recovery of tritium-labeled ribonucleic acids extracted from hybrid gels is 20 to 25% greater than from standard acrylamide-methylenebisacrylamide gels. Standard curves of electrophoretic mobilities as a function of molecular weights of dissociated proteins and ribonucleic acids are compared for acrylamide-agarose gels and acrylamide-methylenebisacrylamide gels.     

肽核酸相关技术在杂交检测中的应用

肽核酸是一种寡核苷酸的类似物,它是由丹麦哥本哈根大学的Ｎｉｅｌｓｅｎ、Ｅｇｈｏｌｍ等人首先发明合成的。肽核酸与传统的寡核苷酸相比,骨架结构发生了根要变化。肽核酸的电中性骨架有许多ＤＮＡ所不具备的性质,例舅高灵敏度、高特异性、非盐依赖性等,从而使它成为一种优良的寡核苷酸的取代物,尤其是杂交检测领域。     

Toward the development of smart and low cost point-of-care biosensors based on screen printed electrodes

Screen printing technology provides a cheap and easy means to fabricate disposable electrochemical devices in bulk quantities which are used for rapid, low-cost, on-site, real-time and recurrent industrial, pharmaceutical or environmental analyses. Recent developments in micro-fabrication and nano-characterization made it possible to screen print reproducible feature on materials including plastics, ceramics and metals. The processed features forms screen-printed disposable biochip (SPDB) upon the application of suitable bio-chemical recognition receptors following appropriate methods. Adequacy of biological and non-biological materials is the key to successful biochip development. We can further improve recognition ability of SPDBs by adopting new screen printed electrode (SPE) configurations. This review covers screen-printing theory with special emphasis on the technical impacts of SPE architectures, surface treatments, operational stability and signal sensitivity. The application of SPE in different areas has also been summarized. The article aims to highlight the state-of-the-art of SPDB at the laboratory scale to enable us in envisaging the deployment of emerging SPDB technology on the commercial scale.     

A fluorimetric method for the determination of nucleic acids using Ce(IV) and sodium triphosphate.

A novel and stable fluorimetric method was established for the determination of nucleic acids. The proposed method is based on the reduction by nucleic acids of Ce(IV) to fluorescent Ce(III). The fluorescence intensity can be greatly increased by sodium triphosphate. The enhanced fluorescence intensity is proportional to the concentration of nucleic acids in the range 4.2 x 10(-8)-4.2 x 10(-6) g/mL for fish sperm DNA and 5.0 x 10(-8)-6.5 x 10(-6) g/mL for yeast RNA, and the detection limits (S/N = 3) are 13.5 ng/mL and 45 ng/mL, respectively. The reaction mechanism of the hydrolytic scission of nucleic acids by Ce(IV) is discussed.