Membrane-oxide semiconductor field-effect transistor (MOSFET) sensors

MOSFET-sensors can be considered as membrane-oxide-semiconductor field-effect transistors. MOSFETs can be divided into ISFETs, GasFETs, BioFETs, these sensors being sensitive to ion, gas, biomolecules respectively and there is also a possibility to fabricate MOSFET reference electrode (RefFET). The development and theoretical treatment of various type of MOSFET-sensors are presented in this paper.     

Chemical diffusion of oxygen in tin dioxide: Effects of dopants and oxygen partial pressure

Tin dioxide SnO_2−δ is a pronounced n-type electron conductor due to its oxygen deficiency. This study investigates the rate of chemical diffusion of oxygen in SnO_2−δ single crystals, which is a crucial step in the overall stoichiometry change of the material. The chemical diffusion coefficient D^δ was determined from conductivity- and EPR-relaxation methods. The temperature dependence was found to be . The dependence on crystal orientation, dopant content and oxygen partial pressure was below experimental error. The latter observation leads to the conclusion that the chemical diffusion coefficient is close to the diffusion coefficient of oxygen vacancies. Along with the relaxation process resulting from the chemical diffusion of oxygen, additional processes were observed. One of these was attributed to complications in the defect chemistry of the material. The relevance of the results for the kinetics of drift processes of Taguchi sensors is discussed.     

Detection of Tumor Necrosis Factor Gene by Piezoelectric Nucleic Acid Senosr

A piezoelectric nucleic acid sensor was constructed ofr detection of tumor necrosis factor gene.Two methods were employed for immobilization of nucleic acid probe on gold electrode of piezoelectric crystal.The results show that polyethyleneimine adbesion and glutaraldehyde cross-linking method has higher sensitivity,stability and selectivity than protein A method.The solid-phase nucleic acid hybridization of oligo unclecotides and tumor necrosis factor target gene sequence were monitorde using this sensor.Tumor necrosis factor gene sequence(580bp) was detected by this nucleic acid sensor for the first time.     

味觉电化学传感器的研究——Ⅰ.甜、酸、苦、咸物质对模拟生物膜电位振动频率的影响

本文以十六烷基三甲基溴化铵/含苦味酸的硝基苯/蔗糖溶液为研究体系,发现甜、酸、苦、咸物质均能使体系的振动波形和频率发生变化,初步建立了测定有味物质的定性、定量方法,并对该味觉电化学传感器的响应机理进行了探讨。     

2,2’-联吡啶-1,1’-二氧化物与Mn(Ⅱ)的三聚体配合物的合成及性能

Mn( )能与许多氮氧化合物形成配合物 ,Wilde对 Mn( )与 2 ,2 -联吡啶及 1 ,1 -二氮杂菲的均配配合物作过详细研究 [1,2 ] ;Mn( )与 2 ,2 -联吡啶 - 1 ,1 -二氧化物 ( bipy O2 )的配合物也有综述 [3] .Mn( )与 bipy O2 的配合物大多是以 Cl O- 4、NO- 3、[Pt Cl4 ]2 -为阴离子 ,少数是卤离子 .它们均形成配位体数目为 3的单核螯合物 ,这些配合物是在水或乙醇中合成的 .Mn( )与 bipy O2 的多核聚合物还未见报道 .本文用 DMF为溶剂 ,以无水 Mn Cl2 和 2 ,2 -联吡啶 - 1 ,1 -二氧化物为原料 ,合成了 Mn( )与bipy O2 的三聚…     

Signaling molecularly imprinted polymers: molecular recognition-based sensing materials

Molecular imprinting is a template polymerization technique that can easily provide synthetic polymers capable of molecular recognition for given target molecules. In addition to their highly specific recognition ability, we are attempting to introduce signaling functions to molecularly imprinted polymers, enabling them to respond according to specific binding events. Some of our work regarding such signaling molecularly imprinted polymers is presented here, including molecularly imprinted polymers that induce spectral shifts of target compounds because of binding. Such compounds include hydrogen-bonding-based fluorescent imprinted polymers and metalloporphyrin-based signaling molecularly imprinted polymers.     

Purification of recombinant green fluorescent protein by three-phase partitioning

The technique of three-phase partitioning (TPP) was used to purify the green fluorescent protein (GFP) in a single step. TPP uses a combination of ammonium sulphate and tert-butanol to precipitate proteins from their crude extracts. In the first round of TPP with 20% ammonium sulphate saturation at the ratio of crude to tert-butanol 1:1 (v/v), most of the GFP remains in the lower aqueous phase. When subjected to a second round of TPP with 60% ammonium sulphate saturation at the ratio of crude to tert-butanol 1:2 (v/v) gives 78% recovery of GFP with a 20-fold purification. The sodium dodecyl sulphate-polyacrylamide gel electrophoretic (SDS-PAGE) analysis of purified preparation shows single band. The fluorescence excitation and emission spectra agreed with values reported in literature.     

小型管道pH传感器的研制及其于自动化在线监测中的应用

研制了数种结构简单、实用的小型管道玻璃膜ｐＨ传感器和小型管道ＰＶＣ膜ｐＨ传感器，并将其与普通的酸度计和自动采样器（自制）等合理组合，构成了自动采样酸度在线监测装置，该装置与计算机自动化控制系统联网，已用于稀土萃取分离槽液的酸度自动化在线监测，结果满意。     

Quantitative study on La~(3+) influx mediated by sodium-calcium exchanger in human lymphocytes

Whether La3+ can enter human peripheral blood lymphocytes by the Na+/Ca2+ exchanger or not and the effect of La3+on the Na+/Ca2+ exchanger activity are examined by fura-2 technique. And that whether La3+ is sequestered by intracellular organelles (mainly endoplasmic reticulum and mitochondria) is studied by this method. La3+uptake is obviously stimulated by pre-treating the cells with ouabain and by removing extracellular Na+, and intracellular La3+concentration ([La3+]i) is directly proportional to its extracellular concentration ([La3+]o). But when [La3+]o exceeds 0.4 mmol/L, the 340/380 nm ratio of fluorescence is no longer varied and the maximum [La3+], is 1.5×10-12 mol · L-1. The higher concentration of La3+ (0.1 mmol/L) increases Na+/Ca2+ exchange-mediated calcium influx, but lower concentration (10 μmol/L) appears to block calcium influx. The results also suggest that cytosolic La3+ is transported by the ATP-dependent Ca2+ pump. Intracellular Ca2+ stores are depleted by ionomycin, and then ion     

Design of Supramolecular Cyclodextrin Complex Sensors for Ion and Molecule Recognition in Water

The design and function of novel supramolecular fluoroionophore/cyclodextrin (CyD) complex sensors for ion and molecule recognition in water are reviewed. For the crown ether fluoroionophore/-CyD complex, the dimerization of the fluoroionophore inside the -CyD is found to be selectively promoted by alkali metal ion binding, thereby resulting in metal-ion-selective pyrene dimer emission in water. This supramolecular function is successfully utilized in the design of a podand fluoroionophore/-CyD complex for sensing toxic lead ion in water. The boronic acid fluoroionophore/-CyD complex binds sugars and produces increased fluorescence emission in water. The response mechanism appears to be due to the suppression of the photoinduced electron transfer (PET) from pyrene donor to trigonal phenylboronic acid acceptor. This is a novel emission function provided by the boronic acid fluoroionophore/-CyD complex sensors in water.