铂黑/二茂铁修饰MEMS电极的葡萄糖传感器

利用MEMS技术小批量加工了薄膜金电极。采用电化学沉积法在金电极表面修饰纳米铂黑颗粒,以有机功能性材料二茂铁作为电子媒介体,通过戊二醛-牛血清白蛋白共价交联固定葡萄糖氧化酶制得葡萄糖生物传感器。考察了不同修饰电极的电化学行为以及酶固定量和戊二醛浓度对传感器响应特性的影响。实验结果表明:该传感器响应时间仅为5s,在0.29V的低工作电压下,线性测量范围可达到0.5～22mmol/L,灵敏度为50.35μA/(cm2.mmol.L-1),相关系数为0.9925,差异系数为4.28%。     

超宽范围的电化学酶生物传感器与检测技术

目前,发酵工业因缺少高效在线检测手段,生产过程中不能及时跟踪底物或产物浓度变化,导致发酵效率低,污染排放严重。电化学酶生物传感器能够实现对生化反应中特定组分浓度的快速精确检测,已广泛应用于医疗行业。然而,该传感器检测范围过窄,在真实发酵体系中,需预先对样品进行稀释处理,仅能实现离线检测。为此,提出一种超宽范围的新型电化学酶生物传感器及检测方法。传感器采用三电极丝网印刷结构,工作电极为自制的规则普鲁士蓝纳米颗粒传感膜及生物酶,检测采用流动注射分析技术。测试表明,该传感器及检测系统对葡萄糖浓度的检测范围为0.5-120g/L,测量误差在2 %以内,测量周期< 60秒,完全满足发酵工业在线检测要求。     

生物恐怖袭击和生物传感器

<正> 2001年最后的三四个月,美国纽约和华盛顿等地屡遭恐怖袭击。这些袭击可分为两类,第一类是“9.11”事件:国际恐怖分子劫持商业航班的飞机作武器,对纽约世界贸易中心两座姐妹摩天大楼和华盛顿的五角大楼进行突然袭击,在一二个小时内就夺去了四千多人的宝贵生命,造成难以估算的损失,给世界经济蒙上了浓浓的阴影,对世界的未来将会产生深远的影响。 第二类恐怖袭击是炭疽孢子袭击。“9.11”事件后的几个月内,纽约、华盛顿等城市不断发现带有炭疽孢子的邮件,一些邮局和几大电视台网的雇员遭到炭疽热的致命袭击,闹得人心惶惶。据说为了应付炭疽袭击,两个月内洛杉矶市就已用去约1400万美元。     

研究人员为检测酒精饮料中的葡萄糖开发新型的生物传感器

随着碳纳米管（CNTs）的独特性能的证实,作为一个有前景的电极材料,单壁碳纳米管的使用受到越来越多的关注。因此,CNT粘贴由充分混合单壁碳纳米管和矿物质而成的电极已经在大量的实例中看到。改进一个适当的催化剂,由此产生电极对于氧化还原的烟酰胺腺嘌呤二核苷酸（NADH）表现出良好的催化活性。结果,     

Highly Sensitive Glucose Biosensors Based on Organic Electrochemical Transistors Using Platinum Gate Electrodes Modified with Enzyme and Nanomaterials

Organic electrochemical transistors with glucose oxidase‐modified Pt gate electrodes are successfully used as highly sensitive glucose sensors. The gate electrodes are modified with nanomaterials (multi‐wall carbon nanotubes or Pt nanoparticles) for the first time, which results in a dramatic improvement in the sensitivity of the devices. The detection limit of the device modified with Pt nanoparticles on the gate electrode is about 5 nM, which is three orders of magnitude better than a device without the nanoparticles. The improvement of the device performance can be attributed to the excellent electrocatalytic properties of the nanomaterials and more effective immobilization of enzyme on the gate electrodes. Based on the same principle, many other types of enzyme sensors with high sensitivity and low cost are expected to be realized by modifying the gate electrodes of organic electrochemical transistors with specific enzymes and nanomaterials.     

Hierachically Structured Hollow Silica Spheres for High Efficiency Immobilization of Enzymes

In this work, the first example of a hierarchically structured hollow silica system is reported without any chemical modification to the enzyme involved in the process. The leaching of the physically adsorbed enzyme is substantially restrained in comparison to pure hollow silica supports. The hierarchical architecture is composed of the ordered hollow silica spheres with a shell‐in‐shell structure. This rationally integrated architecture, which serves as the host for glucose oxidase immobilization, displays many significant advantages, including increases in mechanical stability, enzyme loading, and bioactivity, and a decrease in enzyme leaching compared to existing pure hollow silica matrices. This facilitates further multifarious applications for enhanced enzyme immobilization, biosensors, and biocatalysis.     

Co–Ferrocene MOF/Glucose Oxidase as Cascade Nanozyme for Effective Tumor Therapy

Chemodynamic therapy (CDT), enabling selective therapeutic effects and low side effect, attracts increasing attention in recent years. However, limited intracellular content of H₂O₂ and acid at the tumor site restrains the lasting Fenton reaction and thus the anticancer efficacy of CDT. Herein, a nanoscale Co–ferrocene metal–organic framework (Co‐Fc NMOF) with high Fenton activity is synthesized and combined with glucose oxidase (GOx) to construct a cascade enzymatic/Fenton catalytic platform (Co‐Fc@GOx) for enhanced tumor treatment. In this system, Co‐Fc NMOF not only acts as a versatile and effective delivery cargo of GOx molecules to modulate the reaction conditions, but also possesses excellent Fenton effect for the generation of highly toxic ?OH. In the tumor microenvironment, GOx delivered by Co‐Fc NMOF catalyzes endogenous glucose to gluconic acid and H₂O₂. The intracellular acidity and the on‐site content of H₂O₂ are consequently promoted, which in turn favors the Fenton reaction of Co‐Fc NMOF and enhances the generation of reactive oxygen species (ROS). Both in vitro and in vivo results demonstrate that this cascade enzymatic/Fenton catalytic reaction triggered by Co‐Fc@GOx nanozyme enables remarkable anticancer properties.     

高灵敏度AlGaN/GaN HEMT生物传感器设计及制作

目前AlGaN/GaN高电子迁移率晶体管(HEMT)生物传感器表面修饰及分子识别元件固定需在金属或氧化物门电极上进行,针对金属或氧化物门电极的存在增加了器件的制作难度,提高了制作成本,同时还影响了传感器灵敏度的提高等问题,提出了进行"生物分子膜"门电极的研究。传感器的表面采用3-氨基丙基三乙氧基硅烷(APTES)进行修饰作为分子识别元件固定的基底,该方法在降低传感器的制作成本的同时,提高了传感器的灵敏度,传感区域为长度L=5μm、宽度W=160μm的传感器测量质量浓度为0.1ng/mL的山羊免疫球蛋白(IgG)时,传感器源漏间电流呈现约30μA的电流降。该传感器反应速度快,适用于实时监测,在环境监控、医疗等领域有着良好的应用前景。     

用于甲醛检测的电化学生物传感器的设计

目前用于检测甲醛的传感器有电化学传感器、光学传感器和光生化传感器等。但是当用于实际检测的时候都会存在这样或者那样的问题,比如稳定性差、检出限低、所受干扰物多等等,针对这些问题,文章设计了一种简便、操作简单、适用于实时在线检测甲醛的电化学生物传感器,针对水溶液及混合溶液中甲醛的检测。     

Construction and Characterization of Porous SiO2/Hydrogel Hybrids as Optical Biosensors for Rapid Detection of Bacteria

The use of a new class of hybrid nanomaterials as label‐free optical biosensors for bacteria detection (E. coli K12 as a model system) is demonstrated. The hybrids combine a porous SiO₂ (PSiO₂) optical nanostructure (a Fabry–Pérot thin film) used as the optical transducer element and a hydrogel. The hydrogel, polyacrylamide, is synthesized in situ within the nanostructure inorganic host and conjugated with specific monoclonal antibodies (IgGs) to provide the active component of the biosensor. The immobilization of the IgGs onto the hydrogel via a biotin‐streptavidin system is confirmed by fluorescent labeling experiments and reflective interferometric Fourier transform spectroscopy (RIFTS). Additionally, the immobilized IgGs maintain their immunoactivity and specificity when attached to the sensor surface. Exposure of these modified‐hybrids to the target bacteria results in “direct cell capture” onto the biosensor surface. These specific binding events induce predictable changes in the thin‐film optical interference spectrum of the hybrid. Preliminary studies demonstrate the applicability of these biosensors for the detection of low bacterial concentrations in the range of 10³–10⁵ cell mL^?1 within minutes.