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Mikrochimica Acta

Hua-Ying Chen, Dan Guo, Zhen-Fei Gan, Lei Jiang, Shuai Chang, Da-Wei Li
A surface-enhanced Raman scattering (SERS) based nanoprobe was developed for detection and imaging of endogenous peroxynitrite in living cells. The probe was fabricated by assembling 3-mercaptophenylboronic acid pinacol ester onto the surface of gold nanoparticles (AuNPs). The detection of peroxynitrite is accomplished via measurement of the changes in the SERS spectra (at 882 cm-1 ) that are caused by the reaction between probe and peroxynitrite. The probe has a fast response (<30 s), a 0.4 μM lower detection limit and a wide linearity range from 5...
December 10, 2018: Mikrochimica Acta
Muthaiah Annalakshmi, Paramasivam Balasubramanian, Shen-Ming Chen, Tse-Wei Chen
A glassy carbon electrode (GCE) was modified with a nanocomposite prepared from carboxylated multiwalled carbon nanotubes (c-MWCNT) and titanium nitride (TiN) nanoparticles to obtain a sensor for nitrite. The nanocomposite was characterized by transmission electron microscopy, elemental mapping, X-ray diffraction, and Raman spectroscopy. Electrochemical studies results show the modified GCE to possess a low electrochemical resistance (Rct = 7 Ω) and a large electroactive surface (A = 0.112 cm2 )...
December 10, 2018: Mikrochimica Acta
Yi-Wei Wang, Qiao Liu, Lixing Wang, Shurong Tang, Huang-Hao Yang, Hongbo Song
A one-step reduction method was used for the preparation of stable graphitic carbon nitride-gold nanoparticles (g-C3 N4 -Au) nanocomposites from ultrathin g-C3 N4 nanosheets and chloroauric acid by using NaBH4 as a reducing agent under ultrasonication. The nanocomposites were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis absorption and fluorescence spectroscopy etc. The results revealed that the gold nanoparticles (AuNPs) are uniformly formed on the g-C3 N4 nanosheets...
December 10, 2018: Mikrochimica Acta
Li Zhang, Shaobin Li, Jianjiao Xin, Huiyuan Ma, Haijun Pang, Lichao Tan, Xinming Wang
A Cr-based metal-organic framework MIL-101(Cr) was used to load platinum nanoparticles (PtNPs) that were placed on a glassy carbon electrode (GCE). The modified GCE was used as a non-enzymatic xanthine sensor. Compared to bare GCE, it requires a strongly decreased working potential and an increased signal current for xanthine oxidation. This is due to the crystalline ordered structure and large specific surface of the MIL-101(Cr), and to the high conductivity of the Pt NPs. Differential pulse voltammetry (DPV) shows the sensor to have a wide linear range (0...
December 10, 2018: Mikrochimica Acta
Fahimeh Zeraatkar Kashani, Sayed Mehdi Ghoreishi, Asma Khoobi, Morteza Enhessari
An electrochemical sensor is described for the simultaneous determination of ortho-hydroxybenzoic acid (OHB) and para-hydroxybenzoic acid (PHB). The sensor consists of a carbon paste electrode modified with nickel titanate nanoceramics (NiTiO3 /CPE). The NiTiO3 nanoceramics and the nanostructured modified CPE were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry. Differential pulse voltammetry indicates that the response to OHB (best measured at 0...
December 10, 2018: Mikrochimica Acta
Yanli Huang, Yi Tan, Chuanqi Feng, Shiquan Wang, Huimin Wu, Guangxue Zhang
The preparation of 3 kinds of carbonaceous nanocomposites by hydrothermal treatment and subsequent calcination described. The first comprises a nanomaterial of type CuO/g-C3 N4 , with g-C3 N4 in mass fractions of 2, 5 and 7 wt%, respectively. The second comprises CuO/porous carbon (5 wt%), and the third comprises CuO/carbon spheres (5 wt%). All of them were employed to modify a glassy carbon electrode (GCE) to obtain electrochemical sensors for glucose and dopamine. The GCE modified with CuO/g-C3 N4 (5 wt%) displays the highest electrocatalytic activity towards glucose and dopamine...
December 10, 2018: Mikrochimica Acta
Huihua Guo, Gang Chen, Jiutong Ma, Qiong Jia
A dual-pore covalent organic framework (COF) that contains micropores and mesopores was prepared from 2,4,6-triphenoxy-1,3,5-triazine (TPT). A building block is used in which double linking sites were introduced at each branch of a C3 -symmetric skeleton. The COF is shown to be a viable coating for fibers for solid-phase microextraction of phthalic acid esters (PAEs). Its high specific surface, high hydrophobicity, and wide pore size distribution of a TPT-COF coated fiber result in extraordinarily powerful extraction of PAEs...
December 7, 2018: Mikrochimica Acta
Yanling Hu, Yu He, Yaxue Han, Yili Ge, Gongwu Song, Jiangang Zhou
A rapid method is described for synthesis of copper nanoclusters (CuNCs) by utilizing L-histidine as the stabilizer and ascorbic acid (AA) as the reductant. The CuNCs display blue-green fluorescence with excitation/emission peaks at 390/485 nm. A sensitive fluorometric assay was worked out for determination of alkaline phosphatase (ALP) activity. If the ALP substrate p-nitrophenylphosphate (PNPP) is enzymatically hydrolyzed, it forms p-nitrophenol (PNP) which reduces the fluorescence of CuNCs because its absorption band at 410 nm overlaps the excitation peak of CuNCs at 390 nm...
December 7, 2018: Mikrochimica Acta
Huidan Sun, Shaoyan Wu, Xiaoyan Zhou, Min Zhao, Haiping Wu, Rong Luo, Shijia Ding
A sandwich-type of electrochemical immunoassay is described for the determination of insulin. It is based on the use of a glassy carbon electrode that was modified with MoS2 nanosheets decorated with gold nanoparticles (AuNPs) to immobilize a large amount of first antibody (Ab1 ). Following exposure to insulin, secondary antibody (Ab2 ) that was cross-linked to a DNA initiator strand (T0 ) to form an Ab2 @T0 conjugate was added to undergo a sandwich immunoreaction. Subsequently, the long dsDNA concatemer was formed by a hybridization chain reaction between Ab2 @T0 and auxiliary probes (H1 , H2 )...
December 7, 2018: Mikrochimica Acta
Xingxing Zhang, Qiang Liu, Yan Jin, Baoxin Li
A fluorometric method is described for the determination of the activity of the enzyme T4 polynucleotide kinase phosphatase (T4 PNKP). A short 3'-terminus phosphorylated DNA strand is hybridized with a long DNA strand to produce a partially double-stranded DNA (dsDNA) substrate. On addition of T4 PNKP, the substrate is dephosphorylated to generate the long dsDNA, and then the long dsDNA acted as a template for synthesizing copper nanoclusters (CuNCs). The dsDNA-templated CuNCs display fluorescence with excitation/emission peak wavelengths of 340/570 nm...
December 5, 2018: Mikrochimica Acta
Huan You, Zhaode Mu, Min Zhao, Jing Zhou, Yongjie Chen, Lijuan Bai
This work describes a voltammetric and ultrasensitive aptasensor for sulfadimethoxine (SDM). It is based on signal amplification by making use of a multifunctional fullerene-doped reduced graphene oxide nanohybrid. The nanohybrid was coated with poly(diallyldimethylammonium chloride) to obtain a material (P-C60 -rGO) with large specific surface area and a unique adsorption ability for loading it with glucose oxidase (GOx). The coating also facilitates the direct electron transfer between the active site of GOx and the glassy carbon electrode (GCE)...
December 4, 2018: Mikrochimica Acta
Xuewen Lu, Ting Mei, Qi Guo, Wenjing Zhou, Xiaomei Li, Jitao Chen, Xinke Zhou, Ning Sun, Zhiyuan Fang
The sensitivity of lateral flow assays (LFA) was increased 30-fold by making use of spherical core-shell gold-silica nanoparticles (AuNP@SiO2 NPs). They can be prepared by silylation of surfactant stabilized AuNPs. The AuNP@SiO2 NPs are highly stable and can be used to label antibodies at virtually any concentration. The detection limit of an LFA for alpha-fetoprotein (AFP) can be decreased from 10 ng·mL-1 to 300 pg·mL-1 which makes it comparable to an enzyme-linked immunosorbent assay. To demonstrate the applicability to an immunoassay, a sandwich assay was developed for vanillin by covalent modification of the AuNP@SiO2 NPs with antibody...
December 4, 2018: Mikrochimica Acta
Juan Tang, Lulu Huang, Yu Cheng, Junyang Zhuang, Ping Li, Dianping Tang
A highly sensitive electrochemical sensor is described for the determination of H2 O2 . It is based on based on the use of polyaniline that was generated in-situ and within 1 min on a glassy carbon electrode (GCE) with the aid of the Fe(II)/H2 O2 system. Initially, a 2-dimensional composite was prepared from graphene oxide and polyamidoamine dendrimer through covalent interaction. It was employed as a carrier for Fe(II) ions. Then, the nanocomposite was drop-coated onto the surface of the GCE. When exposed to H2 O2 , the Fe(II) on the GCE is converted to Fe(III), and free hydroxy radicals are formed...
December 1, 2018: Mikrochimica Acta
Ye Hu, Yajiao Huang, Zhengguo Wang, Yanying Wang, Xiaoxue Ye, WingLeung Wong, Chunya Li, Dong Sun
Tungsten disulfide (WS2 ) nanosheets were obtained by exfoliating WS2 bulk crystals in N-methylpyrrolidone by ultrasonication. Gold nanoparticles (GNPs) were synthesized by in-situ ultrasonication of sodium citrate and HAuCl4 while fabricating the WS2 nanosheets. In this way, the GNPs were self-assembled on WS2 nanosheets to form a GNPs/WS2 nanocomposite through interaction between sulfur and gold atoms. The photoelectrochemical response of WS2 nanosheets is significantly enhanced after integration of the GNPs...
December 1, 2018: Mikrochimica Acta
Soodabeh Hassanpour, Behzad Baradaran, Miguel de la Guardia, Amir Baghbanzadeh, Jafar Mosafer, Maryam Hejazi, Ahad Mokhtarzadeh, Mohammad Hasanzadeh
This review (with 145 refs.) summarizes the progress made in the past years in the field of nanomaterial based rapid detection of hepatitis viruses. Following an introduction into the field (with subsection on the significance of hepatitis and on fundamentals of biosensors), conventional methods for detection of hepatitis are discussed, along with their limitationss. The next section covers electrochemical sensors, with subsections on voltammetric, amperometric, potentiometric, impedimetric and conductometric biosensors...
December 1, 2018: Mikrochimica Acta
Fernanda Maria Dos Reis Lima, André da Silva Freires, Neuma das Mercês Pereira, Glaura Goulart Silva, Cláudia Quintino da Rocha, Flavio Santos Damos, Rita de Cássia Silva Luz
The published version of this article, unfortunately, contains an error in that Fig. 2 shows the same study as Fig. 3. The correct Fig. 2 is shown below.
November 29, 2018: Mikrochimica Acta
Xiao-Yu Sun, Run-Tian Ma, Juan Chen, Yan-Ping Shi
Boronate-affinity based molecularly imprinted polymers (MIPs) are beset by the unsatisfied adsorption capacity and narrow working pH ranges. A magnetic molecularly imprinted polymer containing phenylboronic acid groups was placed on the surface of Fe3 O4 (magnetite) microspheres coated with porous TiO2 (Fe3 O4 @pTiO2 @MIP). In contrast to its silica analog (Fe3 O4 @SiO2 @MIP), the flowerlike Fe3 O4 @pTiO2 offers more binding sites for templates. Thus, the adsorption capacity of the Fe3 O4 @pTiO2 @MIP is strongly enhanced...
November 29, 2018: Mikrochimica Acta
Yu Ge, María Belén Camarada, Lanjiao Xu, Mingren Qu, Huan Liang, Erlong Zhao, Mingfang Li, Yangping Wen
A nanocomposite was prepared from graphene-like two-dimensional black phosphorene (BP, an allotrope of phosphorus) and nafion (Nf) treated with isopropanol (IP). A glassy carbon electrode (GCE) modified with this nanocomposite was found to be a viable sensor for voltammetric determination of clenbuterol (CLB). Unlike previously reported pure BP, the BP nanocomposite was stable towards water and oxygen. Its morphology, structure, electrochemically active surface area and electrochemical stability were investigated...
November 29, 2018: Mikrochimica Acta
Yachao Pang, Xiaohuan Zang, Mengting Wang, Qingyun Chang, Shuaihua Zhang, Chun Wang, Zhi Wang
A fibrous magnetic boron nitride nanocomposite was synthesized and is shown to be a viable adsorbent for the magnetic solid phase extraction of pesticides prior to their quantitation by gas chromatography with electron capture detection. The optimum conditions were obtained by both single factor optimization and response surface analysis (Box-Behnken design). Under the optimized conditions, the response to the ten pesticides (dicofol, α-endosulfan, p,p'-DDE, nitrofen, β-endosulfan, p,p'-DDD, p,p'-DDT, bifenthrin, permethrin and fenvalerate) is linear in the 0...
November 28, 2018: Mikrochimica Acta
Haizhu Lin, Hemei Chen, Xi Shao, Chunhui Deng
A zirconium(IV)-based metal organic framework (Zr-MOF) was deposited on polydopamine-coated silica microspheres to form microspheres of type SiO2 @PDA@Zr-MOF. These were packed into capillary columns for enrichment of phosphopeptides. The column was off-line coupled to both matrix-assisted laser desorption/ionization time of flight mass spectrometry and LC-ESI-MS/MS. The method has a detection limit as low as 4 fmol of β-casein digest and a selectivity as high as 1:1000 (molar ratio of β-casein and BSA digest)...
November 28, 2018: Mikrochimica Acta
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