聚甲基丙烯酸甲酯-牛血清白蛋白核壳纳米粒子在金表面的吸附过程及在传感器中的应用

利用铜离子引发体系, 制备出核层为聚甲基丙烯酸甲酯(PMMA)壳层为牛血清白蛋白(BSA)的PMMA-BSA核壳纳米粒子. 通过透射电子显微镜(TEM)表征, 直接观察到PMMA-BSA纳米粒子的核壳结构.结合X射线光电子能谱(XPS)测试, 分析PMMA-BSA纳米粒子的表面成分, 证明PMMA-BSA纳米粒子的壳层是BSA. 利用带耗散的石英晶体微天平(QCM-D)研究了PMMA-BSA纳米粒子在金片表面的吸附行为. 频率的迅速下降, 耗散因子的快速上升, 说明PMMA-BSA粒子快速地吸附到金片表面. 利用磷酸盐缓冲液反复冲洗时, 频率和耗散没有变化, 表明PMMA-BSA 纳米粒子在金片上吸附较牢固. 以金电极为基底电极, 吸附PMMA-BSA纳米粒子后, 利用戊二醛修饰粒子壳层, 再通过氨基与醛基的反应来固定葡萄糖氧化酶, 制备出电流型葡萄糖传感器. 电化学测试表明该传感器对葡萄糖具有良好的电流响应, 在0.3 V的工作电位下, 响应电流与葡萄糖浓度在0.20-5.85 mmol·L^-1范围内呈现出较好的线性关系, 相关系数为0.989. 传感器的灵敏度高达28.6 μA·L·mmol^-1·cm^-2, 响应时间仅为11 s. 传感器还具有良好的稳定性, 在25℃下储存30 d, 响应电流仅下降了16%.     

全新设计蛋白质的折叠机制

蛋白质全新设计和折叠研究是从两个不同的方向来理解蛋白质序列-结构-功能关系这一结构生物学重要问题. 蛋白质全新设计取得的成功实例一定程度上检验了人们对蛋白质结构和相互作用理解的准确性, 但它们中多数所表现的不同于天然蛋白质的折叠动力学特征也表明, 要达到最终的功能化实现目标还面临着不少的挑战. 本文综述了蛋白质全新设计的发展过程及现状, 蛋白质折叠研究在实验、理论及模拟方面的研究进展, 以及全新设计蛋白质的折叠机制的研究现状. 阐述了深入了解全新设计蛋白质与天然蛋白质折叠机制的不同, 可以为进一步有效地合理化设计蛋白质提供有益的参考.     

A Novel Acoustic Emission Fiber Optic Sensor Based on a Single Mode Optical Fiber Coupler

Ａｓｗｅｋｎｏｗ ,ａｓｉｎｇｌｅｍｏｄｅｆｉｂｅｒｃｏｕｐｌｅｒｉｓａｓｉｍｐｌｅｂｕｔｖｅｒｙｉｍｐｏｒｔａｎｔｆｉｂｅｒｏｐｔｉｃｄｅｖｉｃｅ ,ｗｈｉｃｈｃａｎｂｅｕｓｅｄｉｎｃｏｍｍｕｎｉｃａｔｉｏｎａｎｄｓｅｎｓｏｒｓ.Ｕｓｉｎｇｓｉｎｇｌｅｍｏｄｅｏｐｔｉｃａｌｆｉｂｅｒｄｅｖｉｃｅｓ,ｗｅｃａｎｆａｂｒｉｃａｔｅｓｅｖｅｒａｌａｃｏｕｓｔｉｃ ｏｐｔｉｃｄｅｖｉｃｅｓ ,ｓｕｃｈａｓｆｒｅｑｕｅｎｃｙｓｈｉｆｔｅｒｓ ,ｍｏｄｕｌａｔｏｒｓａｎｄｔｕｎａｂｌｅｆｉｌｔｅｒｓ .Ｓｅｖｅｒａｌ…     

A New Approach to Inducing Silicon Tethered Ring-closing Metathesis Reactions

IntroductionGrubbs catalyst bis(tricyclohexylphosphine)benzylidene ruthenium( ) dichloride1 can be usedin a variety of ring- closing metathesis (RCM )reactions,cross metathesis(CM) reactions andring- opening metathesis polymerization(ROMP) [1— 4 ] .It remains metathetically active inthe presence of a variety of functional groups,suchas carbonyls,alcohols,and amides[1] .The use ofcatalyst1 in the synthesis has drawn more andmore attention[5— 13] . However,this catalyst is veryexpensive,an…     

Purification of Single-walled Carbon Nanotubes Grown by a Chemical Vapour Deposition (CVD) Method

ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｎｇｌｅ ｗａｌｌｅｄｃａｒｂｏｎｎａｎｏｔｕｂｅｓ(ＳＷＮＴｓ)ｈａｖｅｂｅｅｎｓｙｎｔｈｅｓｉｓｅｄｂｙｕｓｉｎｇｖａｒｉｏｕｓｍｅｔｈｏｄｓ[1— 3] ａｎｄｔｈｅｃｈｅｍｉｃａｌｖａｐｏｕｒｄｅｐｏｓｉｔｉｏｎ (ＣＶＤ )ｍｅｔｈｏｄｈａｓｂｅｅｎｃｏｎｓｉｄｅｒｅｄａｓａ ｐｒｏｍｉｓｉｎｇｍｅｔｈｏｄｔｏ ｐｒｏｄｕｃｅＳＷＮＴｓｏｎａｎｉｎｄｕｓｔｒｉａｌｓｃａｌｅ[3— 5] .Ｈｏｗｅｖｅｒ ,ａｌｌｔｈｅＳＷＮＴ ｐｒｏｄｕｃｔｓｓｙｎｔｈｅｓｉｓｅｄｔｏｄａｔｅｃｏ…     

Studies on the Interactions between Potassium oxalato-oxodiperoxovanadate and Histidine by NMR and MS

K3[VO(O2)2(C2O4)]2H2O, (abbr. BpV (ox)) pertains to peroxovanadium (abbr. pV) complexes, which have been attracted considerable attention nowadays, since they are inhibitors of tyrosine phosphatase and may be developed into a new kind of drugs for the treatment of diabetes1. According to the evidence on water-biperoxovanadium, the molecular mechanism of insulin-like effects of pV involves in irreversibly oxidizing the catalytic cysteine at the active site of the target enzyme2,3. However…     

Voltammetric Studies of the Interaction of Tris (1,10-phenanthroline) Cobalt (III) with Bovine Serum Albumin

Recently, the studies on the interaction of DNA with small molecules have been attracting much interest1-6. These researches not only gave the important information about thermodynamics and kinetics, but also can prompt the combination between the electrode substances and biomacromolecule with super catalysis and sensor character. It is of great significance in understanding energy conversion and metabolism in live body, biomolecular structure, various physical and chemical characters for e…     

The Synthesis of N-Morphine Hapten and Production of Monoclonal Antibody

The drug overdose and addiction is a serious international problem. Therefore developing a rapid, accurate, convenient and cheap method for detecting morphine in urea is useful and necessary, especially for investigation of epidemiology, identification of medical jurisprudence and determination of drug addict etc. There are many compounds that are similar to morphine in chemical structure and tend to have cross-reaction with the anti-morphine antibody. In order to reduce the cross reaction a…     

Hybrid Composite of Polyaniline Containing Carbon Nanotube

Among various conducting polymers, polyaniline (PANI) is a unique and promising candidate for practical applications because it is not only highly stable in air and in some solvents, but also exhibits dramatic changes in its electronic structure and physical properties in protoactivate state1,2,3. The carbon nanotubes (CNTs) have been proven to possess exotic properties, such as high mechanical strength, flexibility and electric conductivity. The study of carbon-based nanostructures and ma…     

Synthesis of a New β-Mercaptoalcohol

Mercaptoalcohols are a rare class of natural products. Some optically active mercaptoalcohols have been used as catalysts in asymmetric reduction of prochiral Ketone1,2. In this letter, we report the synthesis of a new optically active (-mercaptoalcohols, (R)-1,1-diphenyl-2-mercapto-3-methyl-1-butanol 7, from L- valine.Our first attempt is showed in Scheme 1. According to literature's method L-valine was converted to (S)-2-Hydroxy-3-methylbutanoic acid 21,2. 2 was treated with MeOH/SOCl2…