Au nanowire-on-film SERRS sensor for ultrasensitive Hg2+ detection

We report an ultrasensitive and selective single nanowire-on-film (SNOF) surface-enhanced resonance Raman scattering (SERRS) sensor for Hg(2+) detection based on structure-switching double stranded DNAs (dsDNAs). Binding of Hg(2+) induces conformational changes of the dsDNAs and let a Raman reporter get close to the SNOF structure, thereby turning on SERRS signal. The well-defined SNOF structure provides a detection limit of 100 pM with improved accuracy in Hg(2+) detection. This sensor is stable over a considerable amount of time and reusable after simple treatment. Since this SNOF sensor is composed of a single Au NW on a film, development of a multiplex sensor would be possible by employing NWs modified by multiple kinds of aptamers.     

Simple and accurate quantitative analysis of seven prohibited threshold substances in human urine by liquid chromatography/tandem mass spectrometry in doping control

A simple and accurate liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed and validated for the quantitative determination of ephedrine, pseudoephedrine, methylephedrine, cathine, salbutamol, morphine and epitestosterone in human urine. Urine samples were spiked with internal standard and diluted with acetonitrile. After centrifugation, the supernatants were directly analyzed by LC/MS/MS using the selected reaction monitoring (SRM) mode. The linearity, intra- and inter-day precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ) were evaluated and the method was found to be accurate and reproducible for the quantitation of threshold substances. When the method was applied to the analysis of blind urine samples for the proficiency test, the results were close to the nominal concentrations, within 87.7-106.6% of nominal values, suggesting that the developed methods can be successfully applied to routine doping analyses.     

Detection of single nucleotide polymorphisms by a gold nanowire-on-film SERS sensor coupled with S1 nuclease treatment

Single nucleotide polymorphisms (SNPs) can serve as important biomarkers for genetic diseases, for which accurate detection of SNPs is essential for early diagnosis. We have developed a novel SNP sensor by combining a Au nanowire-on-film surface-enhanced Raman scattering (SERS) platform with S1 nuclease reaction. The combined sensor system provides reproducible SERS signals only in the presence of perfectly matched target DNAs, to probe DNAs as a result of single-stranded DNA-specific degradation by S1 nuclease. Furthermore, point mutations in DNA causing Wilson disease and Avellino corneal dystrophy were successfully identified by this sensor, thereby indicating its practical ability to diagnose genetic diseases.     

Chemical and thermal stability of isotypic metal-organic frameworks: effect of metal ions

Chemical and thermal stabilities of isotypic metal-organic frameworks (MOFs) like Al-BDC (Al-benzenedicarboxylate called MIL-53-Al), Cr-BDC (MIL-53-Cr) and V-BDC (MIL-47-V), after purification to remove uncoordinated organic linkers, have been compared to understand the effect of the central metal ions on the stabilities of the porous MOF-type materials. Chemical stability to acids, bases, and water decreases in the order of Cr-BDC>Al-BDC>V-BDC, suggesting stability increases with increasing inertness of the central metal ions. However, thermal stability decreases in the order of Al-BDC>Cr-BDC> V-BDC, and this tendency may be explained by the strength of the metal-oxygen bond in common oxides like Al(2)O(3), Cr(2)O(3), and V(2)O(5). In order to evaluate precisely the stability of a MOF, it is necessary to remove uncoordinated organic linkers that are located in the pores of the MOF, because a filled MOF may be more stable than the same MOF after purification.     

2009Pittcon会议(Ⅱ)

传感器与传感整合系统组的报告有:(1)Ashvarev,应用脉冲电极作离子选择电极的无偏压选择性测定;(2)R de Marco,离子选择性原子X显微术--一种新的材料鉴定技术;(3)S P Kounares,应用离子选择性电极分析火星表面;(4)M DPietrazak,以Rh(Ⅲ)络合物为基础的选择性测定NO2-的电化与学光传感器;(5)E Baker,聚合物膜离子传感器的电化激发;(6)A Raclu,应用电化阻抗谱探测离子选择膜的功能性质与程度;(7)MGratzl,在活体民试管中进行以光极为基础的银传感器试验,应用于型小实验室中的动物代谢监测.     

超支化聚磷酸酯阻燃剂对尼龙6的成炭促进作用

以三氯氧磷和双酚A为原料制备了具有超支化结构的聚磷酸酯阻燃剂(HPPEA),通过红外(FTIR),核磁(1H-NMR,31P-NMR)及热重分析表征了产物的结构和热稳定性.将HPPEA与三聚氰胺聚磷酸盐(MPP)进行复配,通过熔融共混法制备阻燃尼龙6,通过氧指数法和垂直燃烧法测试了其阻燃性能,采用热重分析(TGA)研究...     

热处理对La0.63Gd0.2Mg0.17Ni3.1Co0.3Al0.1储氢合金微观组织和电化学性能的影响

在氩气气氛和1173 K保温条件下对La0.63 Gd0.2 Mg0.17Ni3.1 Co0.3 Al0.1储氢合金进行不同时间(t=8 ～168 h)的热处理,采用电感耦合等离子发射光谱(ICP)、X射线衍射(XRD)、电子探针显微分析方法(EPMA)和电化学测试分析方法对比研究了退火时间对合金显微组织演化和电化学性能的影响.研究结果表明,铸态合金组织由Ce2 Ni7型、Gd2Co7型、Pr5 Co19型、PuNi3型和CaCu5型相组成,其Ce2 Ni7型相的丰度为78.9％,随退火时间的延长,退火合金中Ce2 Ni7型相的丰度逐渐增加,当退火时间t=168 h时其相丰度达到94.5％,Ce2 Ni7型相结构的晶胞参数和晶胞体积随退火时间增加而减小.电化学测试分析表明,退火合金电极的电化学性能与Ce2 Ni7型相的丰度有密切关系,退火时间对合金电极的活化性能影响不大,但合金电极放电容量随退火时间的延长逐渐提高,当t=168 h时,合金电极放电容量达到最大值386.8mAh·g-1;退火时间对合金电极循环稳定性的提高和改善有不同程度的影响,当退火时间t=16～168 h时,经100次充放电循环后,其电极容量保持率S100=90.3％～91.5％.热处理能有效改善合金电极电化学反应的动力学性能,但不同退火时间对合金电极的高倍率放电性能影响不明显.     

A multistage pathway for human prion protein aggregation in vitro: from multimeric seeds to β-oligomers and nonfibrillar structures

Aberrant protein aggregation causes numerous neurological diseases including Creutzfeldt-Jakob disease (CJD), but the aggregation mechanisms remain poorly understood. Here, we report AFM results on the formation pathways of β-oligomers and nonfibrillar aggregates from wild-type full-length recombinant human prion protein (WT) and an insertion mutant (10OR) with five additional octapeptide repeats linked to familial CJD. Upon partial denaturing, seeds consisting of 3-4 monomers quickly appeared. Oligomers of ~11-22 monomers then formed through direct interaction of seeds, rather than by subsequent monomer attachment. All larger aggregates formed through association of these β-oligomers. Although both WT and 10OR exhibited identical aggregation mechanisms, the latter oligomerized faster due to lower solubility and, hence, thermodynamic stability. This novel aggregation pathway has implications for prion diseases as well as others caused by protein aggregation.