免疫型光纤倏逝波生物传感器的研究与发展

介绍了基于倏逝波激发的荧光免疫型光纤生物传感器的基本原理,针对其中应用的各种方法进行了分析。基于倏逝波激发的荧光免疫型光纤生物传感器的免疫检测方法、探头发展和系统结构发展．对国内外的最新产品和技术及其应用情况进行了介绍和概述,并结合新技术的出现和系统整体结构的演变趋势对免疫型倏逝波光纤生物传感器的发展进行了展望。     

Design of Readout Circuit Based on Probe Neural Biosensor

According to the characteristics of neural signal,a low-voltage and high-speed operational transconductance amplifier has been realized as a direct readout circuit. To reduce the size and cost of this chip, the amplifier uses feedforward compensation technique without Miller capacitor. Using capacitors as a closed-loop feedback not only amplifies the neural signal, but also reduces chip power consumption by replacing the feedback resistor. Simulations were carried out with 0.18m CMOS technology, and the simulation results satisfied the requirements of neural signal.     

基于光栅波导共振耦合的传感器特性研究

该文设计了一种基于光栅波导共振角耦合的生物传感器,通过光栅波导模式谱变化检测传感器表面有效折射率变化的方式,实现了传感器表面附着物的精确检测。并在平板介质光波导理论基础上,推导了三、四层结构理论模型,实验得到了入射角与检测溶液折射率及入射角与分子膜层厚度间的变化关系。结果表明,光栅波导共振角耦合生物传感器入射角与待测溶液折射率存在良好的线性关系,并具有较高灵敏度,精度可达0.01(°)/nm。通过该方法制作出无标记的生物传感器,能广泛应用于生物分子检测,尤其适合蛋白质分子生物检测。     

Application of biosensors in early detection of contamination with lactic acid bacteria during apple juice and concentrate production

The aim of Collective Research Project QUALI-JUICE (COLL-CT-2005, Co Nr 012461) was to introduce the biosensors in control of microbiologically pure apple juice production. Three commercial lactate biosensors were used and compared with enzyme kits assays. Parallel the microbiological analysis of the production process at one juice producing enterprise was done. The results of lactic acid assay with biosensors were in good correlation with those obtained by enzyme kits. The main benefit of biosensor use was shortening of measurement time as compared with assay by enzyme kit and possibility to measure at line. The concentration of l-lactic acid in apple pulp could be correlated with the number of lactic acid bacteria. Pasteurization process was eliminating lactic acid bacteria and the concentration of lactic acid was at this stage not exceeding 0.1 g L⁻¹. The final product (apple concentrate) contained in some cases very high amounts of lactic acid indicating secondary microbiological contamination after pasteurization step. Parallel microbiological analysis of production process and lactate assay indicated that the critical point during production was prolonged vacuum filtration after pasteurization.     

Design of an integrated low-noise read-out system for DNA capacitive sensors

This paper presents an electronic system for a fast DNA label-less detection. The sensitivity of the capacitive sensor in use is improved by depositing an insulating self-assembled monolayer (SAM) over the golden electrodes. The capacitance shift due to the hybridization effect is monitored by means of a charge-sensitive amplifier and digitalized by means of a comparator and a counter. The read-out solution demonstrates the ability to identify a 0.01% variation on the capacitive value of the sensor. Results from measurements with the optimized sensor show the reliability of the electronics. The investigated solution is suitable for monolithic systems or for a micro-fabricated array of sensors. An example of the integrated front-end is described and performances and noise evaluation are reported here.     

Amperometric Cholesterol Biosensor Using Layer-by-Layer Adsorption Technique on Polyaniline-coated Polyester Films

An amperometric cholesterol biosensor was fabricated using polyaniline-coated polyester films. Polyaniline was dissolved in chloroform with camphorsulfonic acid, and polystyrene was added to this solution. Using this mixed solution, the coating was placed onto polyester films. Cholesterol oxidase was immobilized onto these films using an electrostatic layer-by-layer adsorption technique. Poly(diallyldimethylammonium chloride) was used as the counter ion source. The level of adsorption was examined and evidence of layer-by-layer adsorption was investigated using a quartz crystal microbalance (QCM). A cholesterol biosensor was fabricated from these films as a working electrode, and it was used to measure the cholesterol concentration.