基于T-T碱基错配的荧光传感器特异性检测汞离子

在本文中,我们研制了一种基于T-T碱基错配特异性键合汞离子的荧光传感器用于汞离子的检测。该传感器由两条分别标记了荧光基团（F）和淬灭基团（Q）的DNA探针组成,并且含有两对用于结合汞离子的T-T错配碱基。当汞离子存在时,两条探针之间形成T-Hg2+-T结构,作用力增强,从而拉近了荧光基团与淬灭基团之间的距离,发生能量转移,使荧光信号在一定程度上被淬灭。在优化的条件下,我们使用该传感器对汞离子进行检测,动力学响应范围为50nM到1000nM,线性相关方程为y= 5281.13 - 1650.56 lg[Hg2+] ( R2 = 0.985),检测下限为79nM。此外,我们还考察了该传感器的选择性,当用其它干扰离子（浓度都为1.0µM）代替待测离子进行实验时,没有发生明显的荧光淬灭,说明该传感器具有较高的选择性。该传感器的构建为汞离子的检测提供了一条快速、简便的新途径。     

基于酶催化沉积放大的电化学阻抗法用于人免疫球蛋白M的检测

提出了一种基于酶催化沉积放大的电化学免疫分析方法。先通过免疫夹心反应,将酶标抗体(羊抗人IgM-HRP)固定到电极表面。通过HRP催化双氧水氧化3,3′-二氨基联苯胺在电极表面形成不溶性沉积物,从而放大电化学检测信号。实验通过蛋白A实现抗体的定向固定。考察了包被抗体的浓度和包被溶液的pH对抗体固定的影响,以及酶标抗体的用量和沉积时间对免疫分析的影响。传感器信号响应与人免疫球蛋白M(IgM)浓度在2.1~670μg/L范围内具有良好的线性关系;检出限达0.08μg/L。     

基于甲基丙烯酰胺基芘荧光载体光聚合膜的奥硝唑传感器

合成了一种端基烯键的芘衍生物荧光载体-甲基丙烯酰胺基芘(MAAP)。基于光聚合反应将该荧光载体共聚固定于玻片表面,利用奥硝唑对共价固定膜甲基丙烯酰胺基芘的熄灭作用,研制了一种测定奥硝唑的荧光传感器。传感器避免了荧光载体的泄漏,具有较好的稳定性、重现性和选择性,使用寿命长。奥硝唑测定的线性范围为1.0×10-6~1.0×10-3mol/L;检出限为4.0×10-7mol/L;将传感器用于水样中奥硝唑的直接测定,回收率在93.8%~110.5%。     

α-蒎烯水合主产物的分离与提纯

根据α-蒎烯水合产物中的龙脑、异龙脑和α-松油醇在邻苯二甲酸酐存在下发生酯化、脱水反应的选择性差异，可将三者大部分分离，提高优质龙脑和α-松油醇的得率。．     

微量元素硒的临床应用和研究

简述了近年来硒的临床应用和研究概况，主要内容涉及到硒在抗衰老，治疗病毒性肝炎和肿瘤中的应用以及硒的补充。     

Formulas for approximating pseudo-Boolean random variables

We consider {0,1}ⁿ as a sample space with a probability measure on it, thus making pseudo-Boolean functions into random variables. We then derive explicit formulas for approximating a pseudo-Boolean random variable by a linear function if the measure is permutation-invariant, and by a function of degree at most k if the measure is a product measure. These formulas generalize results due to Hammer-Holzman and Grabisch-Marichal-Roubens. We also derive a formula for the best faithful linear approximation that extends a result due to Charnes-Golany-Keane-Rousseau concerning generalized Shapley values. We show that a theorem of Hammer-Holzman that states that a pseudo-Boolean function and its best approximation of degree at most k have the same derivatives up to order k does not generalize to this setting for arbitrary probability measures, but does generalize if the probability measure is a product measure.     

Gold nanoparticle based signal enhancement liquid crystal biosensors for DNA hybridization assays

A novel signal enhanced liquid crystal biosensor based on using AuNPs for highly sensitive DNA detection has been developed. This biosensor not only significantly decreases the detection limit, but also offers a simple detection process and shows a good selectivity to distinguish perfectly matched target DNA from two-base mismatched DNA.     

Molecularly imprinted TiO(2) thin film using stable ground-state complex as template as applied to selective electrochemical determination of mercury

Molecular recognition sites for mercury ions were imprinted in TiO₂ film using stable ground-state complex of 1-amino-8-naphtol-3,6-disodium sulfonate (ANDS) and mercury ions as template. The complex ratio between mercury ions and ANDS was estimated to be 2:1. Compared with the controlled and pure TiO₂ electrodes, the imprinted electrode revealed selectivity towards the imprinted ions. Linear calibration plots for mercury ions were obtained and the regression equation was I_p (μA) = 4.29 × 10⁻⁷ + 19.40 [Hg²⁺] with a detection limit of 3.06 × 10⁻⁹ mol/l. The imprinted electrode could be used for more than 1 month. Recoveries were calculated at both high and low concentrations, with a mean recovery of 99.6%.     

ZnO-based hollow microspheres: biopolymer-assisted assemblies from ZnO nanorods

Many efforts have been made in fabricating three-dimensional (3D) ordered zinc oxide (ZnO) nanostructures due to their growing applications in separations, sensors, catalysis, bioscience, and photonics. Here, we developed a new synthetic route to 3D ZnO-based hollow microspheres by a facile solution-based method through a water-soluble biopolymer (sodium alginate) assisted assembly from ZnO nanorods. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and X-ray photoelectron spectroscopy. Raman and photoluminescence spectra of the ZnO-based hollow microspheres were obtained at room temperature to investigate their optical properties. The hollow microspheres exhibit exciting emission features with a wide band covering nearly all the visible region. The calculated CIE (Commission Internationale d'Eclairage) coordinates are 0.24 and 0.31, which fall at the edge of the white region (the 1931 CIE diagram). A possible growth mechanism of the 3D ZnO superstructures based on typical biopolymer-crystal interactions in aqueous solution is tentatively proposed, which might be really interesting because of the participation of the biopolymer. The results show that this biopolymer-directed crystal growth and mediated self-assembly of nanocrystals may provide promising routes to rational synthesis of various ordered inorganic and inorganic-organic hybrid materials with complex form and structural specialization.