硫酸软骨素ABC I酶的融合表达及传感器应用研究

采用MiSeq高通量测序技术对来凤地区盐渍藠头盐水细菌多样性进行解析，并采用PICRUSt技术对其基因功能进行预测。结果表明，99.58%的基因序列长度为425～451 bp，基本覆盖16S rRNA V3-V4区序列；优势细菌门为硬壁菌门（Firmicutes）、变形菌门（Proteobacteria）和放线菌门（Actinobacteria），平均相对含量分别为43.94%、33.12%和18.21%；优势细菌属为乳杆菌属（Lactobacillus）、假单胞菌属（Pseudomonas）和嗜热油菌属（Thermoleophilum），平均相对含量分别为30.28%、18.21%和16.13%；共有219个核心操作分类单元（OTU），包含的序列数占总序列数的75.56%；盐渍藠头盐水中可能共有大量具有较强氨基酸转运和代谢功能的细菌类群。     

食源性致病菌单增李斯特菌检测技术的研究进展

单增李斯特菌是一种兼性厌氧性食源性致病菌,对低温、高盐及消毒剂的抵抗力很强,感染后可能产生低热、高热或其他全身性疾病,免疫力低下的人可能会引起肠胃炎、孕妇流产、早产或死产,甚至会产生脑膜炎。LM的传统检测方法是先进行增菌,再经过氧化氢酶试验、溶血试验、血清学试验等进行鉴定,操作性强、灵敏度高、成本低,但是检测周期长达7 d,无法对目标食物进行快速检测。本文综述了振动光谱学检测方法、免疫学检测方法、分子生物学检测方法、代谢组学检测法、生物传感器等食源性单增李斯特菌的检测方法,并比较其优缺点,以期为食品中LM的快速检测方法的研究提供参考。     

鸟嘌呤四链体DNAzyme在微生物、生物小分子和核酸检测中的研究进展

鸟嘌呤四链体脱氧核酶(deoxyribozyme,DNAzyme)是一种具有类过氧化物酶催化活性的脱氧核酶,广泛应用于微生物和核酸的分析与检测中。鸟嘌呤四链体DNAzyme在H_2O_2存在时可以催化氧化ABTS、TMB等底物,结合PCR、等温扩增技术以及生物传感器等多种核酸靶标信号放大技术实现待测靶标的便捷灵敏的可视化检测,因此受到了国内外研究者们的高度关注。优化鸟嘌呤四链体的序列和环境因素,能够提高该DNAzyme的催化活性,有助于提高可视化检测方法的灵敏度。本文主要对鸟嘌呤四链体DNAzyme的结构与酶学性质及其应用于微生物、生物毒素和疾病标志物等的基于核酸的检测策略进行综述,为进一步推动鸟嘌呤四链体DNAzyme的广泛应用提供理论基础和技术支持。     

静电纺丝法制备ZnO构建酪氨酸酶生物传感器检测邻苯二酚

电化学生物传感器在环境监测、生物与食品分析等领域应用广泛。本文采用静电纺丝法制备了氧化锌微纳米纤维材料，并负载酪氨酸酶（Tyr）构建了检测邻苯二酚的生物传感电极。利用X射线粉末衍射（XRD）、扫描电子显微镜（SEM）表征了氧化锌微纳米纤维的形貌结构，采用循环伏安法（CV）和计时电流法（IT）优化了检测邻苯二酚的工作条件。结果表明，制备的Tyr/ZnO/CS/GCE生物传感电极具有良好的电化学性能，在反应过程中为扩散控制，对邻苯二酚的检测在5～50μmol/L的浓度范围内具有较好的线性关系，最低检测限为1.9041μmol/L，灵敏度为376.31μA/(mmol·L·cm²)，氧化锌的加入可增强酪氨酸酶的稳定性，在尿素、多巴胺和葡萄糖3种电化学活性相近物质存在的情况下仍对邻苯二酚的检测有较好的选择性，且具有良好的循环稳定性。     

A novel electrochemical aptasensor based on layer-by-layer assembly of DNA-Au@Ag conjugates for rapid detection of aflatoxin M1 in milk samples

Aflatoxin M₁ (AFM₁) is a common toxin in dairy products that causes acute and chronic human health disorders. Thus, the development of a rapid and accurate AFM₁ detection method is of vital importance for food safety monitoring. This work was to develop a novel electrochemical aptasensor for sensitive and specific determination of AFM_1. The dendritic-like nanostructure was formed on the gold electrode surface by layer-by-layer assembly of gold-silver core-shell nanoparticles modified with DNA conjugates. In the presence of AFM₁, the specific recognition between AFM₁ and Apt caused the disassociation of the DNA controlled dual Au@Ag conjugates from the surface of the electrode, causing less methylene blue to bind to the surface and weakening the electrochemical signal. The more AFM₁ there is, the weaker the electrochemical signal. Transmission electron microscope results showed that the successfully synthesized Au@Ag nanoparticles exhibited a core-shell structure with Au as core and Ag as shell, and their average diameter was about 30 nm. Under optimal conditions, the electrochemical aptasensor showed a wide detection ranging from 0.05 ng mL^?1 to 200 ng mL^?1, and a low detection limit of 0.02 ng mL^?1. Moreover, the proposed strategy has been successfully applied to the detection of AFM₁ in cow, goat, and sheep milk samples with satisfactory recoveries ranging from 91.10% to 104.05%. This work can provide a novel rapid detection method for AFM₁, and also provide a new sensing platform for the detection of other toxins.     

Microbial fuel cell (MFC)-based biosensor for combined heavy metals monitoring and associated bioelectrochemical process

To explore the feasibility and related mechanism of MFC biosensor for wastewater detection under the action of combined heavy metals. Cyclic voltammetry (CV) and scanning electrochemical impedance spectroscopy (EIS) were used to explore the related bioelectrochemical process. The response of the reactor to single/combined heavy metals, low/high heavy metal concentrations, and the differences in ohmic resistance (Rs) and charge transfer resistance (Rct) were investigated using Ni as the core heavy metal and the combined action of Cd, Cu and Zn. The results indicated that there was a linear relationship between the concentration and output voltage of the MFC biosensor under the action of combined heavy metals (R² = 0.8803–0.973). However, the internal resistance (Rint) of the MFC biosensor under the action of single heavy metal was far less than that of the combined heavy metal group, and the power density (19.849 W m^?3) was 4 times that of the combined heavy metal group (3.109–4.589 W m^?3). The Rs of the biosensors in the combined heavy metal group were 0.868Ω and 0.860, which were higher than 0.768Ω of the single heavy metal sensor. With the increase of the concentration of heavy metals in the influent, the increase of Rct was more obvious in the combined group, while the Rs in the single group significantly increased (P < 0.05). The results imply that it is possible for MFC biosensors to be used in the detection of actual water polluted by various heavy metals, but the biosensor performance is mainly limited by Rct, which needs to be further improved.     

新型碳纳米材料在电化学免疫传感器的应用

近十几年来,随着免疫检测技术、传感技术和碳纳米材料合成技术的发展,碳纳米材料修饰的电化学免疫传感器得到了广泛的应用和发展。文章简述了碳纳米管、碳纳米球、石墨烯、碳纳米角和碳纳米纤维这5种新型碳纳米材料在构建电化学免疫传感器上的应用进展,并对碳纳米材料修饰的电化学免疫传感器的发展前景进行了展望。     

石墨烯量子点在生物传感和成像技术中的应用

石墨烯量子点具有许多吸引人的优点,如低细胞毒性、溶解能力强、稳定的光致发光、良好的生物相容性、高比表面积、电子高迁移率和可调节带隙等,因此,适用于构建传感系统和生物成像。根据近几年来,基于石墨烯量子点性质构建的光学生物传感器和电化学生物传感器以及石墨烯量子点在生物成像技术中的应用进行了综述。     

免疫空调系统的构建及其初步分析

基于建筑环境安全性的要求，提出了免疫空调系统的概念。免疫空调系统的构建原则为：热湿分开处理(独立除湿)、空气净化与杀菌消毒的综合集成处理、合理的空调系统形式与布置、新风可调以及紧急免疫。给出了两种可行的免疫空调系统形式：溶液独立除湿与蒸发冷却联合运行的系统、溶液独立除湿与机械制冷联合运行的系统。免疫空调系统具有盐水溶液的净化杀菌、设置紫外线杀菌装置、生物传感器检测有疫情出现时系统转入全新风运行等多重净化免疫机制。对所构建的免疫空调系统在运行费用、适用性等方面进行了初步分析，表明其具有较好的经济性和适用性。