Read by QxMD icon Read

Mikrochimica Acta

María Dolores Petit-Domínguez, Carmen Quintana, Luis Vázquez, María Del Pozo, Isabel Cuadrado, Ana María Parra-Alfambra, Elena Casero
The authors describe an electrochemical sensor based on the use of diamond nanoparticles (DNPs) and molybdenum disulfide (MoS2 ) platelets. The sensor was applied to the voltammetric determination of the anticonvulsant valproic acid which was previously derivatized with ferrocene. The MoS2 platelets were obtained by an exfoliation method, and the DNPs were directly dispersed in water and subsequently deposited on a glassy carbon electrode (GCE). The sensor response was optimized in terms of the solvent employed for dispersing the MoS2 nanomaterial and the method for modifying the GCE...
June 22, 2018: Mikrochimica Acta
Neda Ghafori Nia, Azadeh Azadbakht
A composite was prepared from PtSn nanoparticles and carbon nanotubes (PtSnNP/CNTs) and applied to the electrochemical determination of myoglobin (Mb). An Mb-aptamer was immobilized on a glassy carbon electrode (GCE), and hexcyanoferrate was used as an electrochemical probe. The PtSnNP/CNTs were synthesized by a microwave-aided ethylene glycol reduction method. Detection is based on electron transfer inhibition that is caused by the folding and conformational change of the Mb-aptamer in the presence of Mb. The amperometric signal for hexacyanoferrate, best measured at 0...
June 21, 2018: Mikrochimica Acta
Qiao Cheng, Yu He, Yili Ge, Jiangang Zhou, Gongwu Song
A composite (Ag-g-CNQDs) was prepared from graphitic carbon nitride quantum dots and silver nanoparticles by water phase synthesis. Aided by metal-enhanced fluorescence, the composite exhibits excitation-dependent red emission with a peak at 600 nm with a quantum yield of 21%. If the composite is coated with polyethylenimine (PEI) to form the Ag-g-CNQD/PEI complexe, fluorescence is strongly reduced. Upon addition of heparin, the fluorescence of the system is enhanced because PEI has a higher affinity for heparin than Ag-g-CNQDs...
June 20, 2018: Mikrochimica Acta
Zhao Yu, Michael E Smith, Jinnan Zhang, Yan Zhou, Peng Zhang
A surface-enhanced Raman scattering (SERS) method has been developed to determine the concentration of trichloroethylene (TCE) in environmental water. Au-core/Ag-shell nanoparticles containing 4-mercaptophenylboronic acid (4-MPBA) between the core and shell are used as the SERS substrate. 4-MPBA serves as an internal reference with a Raman shift at 534 cm-1 . TCE reacts with 4-mercaptopyridine (4-MPy) in a so-called Fujiwara reaction. With the presence of TCE in water, the consumption of 4-MPy results in a change in the intensity of its Raman signal at 1220 cm-1 ...
June 18, 2018: Mikrochimica Acta
Yanting Nie, Mengyuan Yang, Yiling Ding
The authors describe a method for enhancing the hybridization chain reaction (HCR) by using gold nanoparticles (AuNPs). This can considerably improve the sensitivity of electrochemical immunoassays as demonstrated for the carbohydrate antigen 125 (CA125), a biomarker for ovarian cancer. Compared to previous HCR based assays, the DNA acting as fuel strands were immobilized onto AuNPs, so that dendrimeric like chains were formed on the electrode after HCR. The improved signal is due to the reaction of DNA on the electrode...
June 18, 2018: Mikrochimica Acta
Jiasheng Wang, Ni Hui
A non-fouling electrochemical immunosensor is described for determination of the tumor biomarker carcinoembryonic antigen (CEA). It is based on the use of composite wires made by chemical grafting of hyaluronic acid onto polyaniline nanowires. The modified nanowires possess excellent antifouling property both in single protein solutions and in dilute serum samples. The current of immunoelectrode exhibits a linear response in the 0.01 pg mL-1 to 10,000 pg mL-1 CEA concentration range and 0.0075 pg mL-1 detection limit...
June 16, 2018: Mikrochimica Acta
Xiaohui Niu, Zunli Mo, Xing Yang, Mingyuan Sun, Pan Zhao, Zhenliang Li, Meixuan Ouyang, Zhenyu Liu, Huhu Gao, Ruibin Guo, Nijuan Liu
β-Cyclodextrin (β-CD) possess a hydrophobic inner cavity and a hydrophilic exterior surface. They exhibit excellent inclusion properties with the guest molecules that match cavity size, and β-CD-based materials drew widespread attention in electrochemical sensors. The hydroxy groups at the edge of the cavity can form hydrogen bonds and undergo electrostatic and dipole-dipole interactions with other molecules. This review (with 109 refs.) reveals β-CD-based detection mechanisms from the viewpoint of the size/shape-fit concept, and summarizes the current state of multiple electrochemical sensors based on the use of β-CD and functionalized β-CD such as carboxymethyl-β-CD, mono-(6-ethanediamine-6-deoxy)-β-CD, hydroxypropyl-β-CD, thio-β-cyclodextrin, and others...
June 16, 2018: Mikrochimica Acta
Hongmei Liu, Anxiang Lu, Hailong Fu, Bingru Li, Meihua Yang, Jihua Wang, Yunxia Luan
A novel adsorbent is described for magnetic solid-phase extraction (MSPE) of the aflatoxins AFB1 and AFB2 (AFBs). Magnetic agarose microspheres (MAMs) were functionalized with an aptamer to bind the AFBs which then were quantified by HPLC and on-line post-column photochemical derivatization with fluorescence detection. Streptavidin-conjugated MAMs were synthesized first by a highly reproducible strategy. They possess strong magnetism and high surface area. The MAMs were characterized by transmission electron microscopy, scanning electron microscopy, optical microscopy, laser diffraction particle size analyzer, Fourier transform infrared spectrometry, vibrating sample magnetometry and laser scanning confocal microscopy...
June 12, 2018: Mikrochimica Acta
Fengling Zhang, Hongbin Zhong, Ying Lin, Miaoxuan Chen, Qingshui Wang, Yao Lin, Jiyi Huang
An enzyme-free electrochemical immunoassay is described for the neutrophil gelatinase-associated lipocalin (NGAL; a biomarker of kidney disease). Prussian Blue (PB) nanoparticles with redox activity were deposited on graphitic C3 N4 nanosheets (g-C3 N4 ) by in-situ reduction. A screen printed electrode (SPCE) was modified with antibody against NGAL, and the PB-g-C3 N4 nanohybrid was used as the signal-generating tag for the secondary antibody against NGAL. Upon addition of target NGAL and of secondary antibody, a sandwich is formed on the SPCE...
June 12, 2018: Mikrochimica Acta
Xumin Xu, Xiaoyuan Ma, Haitao Wang, Zhouping Wang
The authors describe a surface-enhanced Raman scattering (SERS) based aptasensor for Salmonella typhimurium (S. typhimurium). Gold nanoparticles (AuNPs; 35 nm i.d.) were functionalized with the aptamer (ssDNA 1) and used as the capture probe, while smaller (15 nm) AuNPs were modified with a Cy3-labeled complementary sequence (ssDNA 2) and used as the signalling probe. The asymmetric gold nanodimers (AuNDs) were assemblied with the Raman signal probe and the capture probe via hybridization of the complementary ssDNAs...
June 12, 2018: Mikrochimica Acta
Kingkan Pungjunun, Sudkate Chaiyo, Issarapong Jantrahong, Siriwan Nantaphol, Weena Siangproh, Orawon Chailapakul
A multistep paper-based analytical device (mPAD) was designed and applied to the voltammetric determination of total inorganic arsenic. The electrodeposition of gold nanoparticles on a boron-doped diamond (AuNP/BDD) electrode and the determination of total inorganic arsenic is accomplished with a single device. Total inorganic arsenic can be determined by first reducing As(V) to As(III) using thiosulfate in 1.0 mol L-1 HCl. As(III) is then deposited on the electrode surface, and total inorganic arsenic is quantified as As(III) by square-wave anodic stripping voltammetry the potential range between -0...
June 11, 2018: Mikrochimica Acta
Gonzalo Martínez-García, Esther Sánchez-Tirado, Araceli González-Cortés, Paloma Yáñez-Sedeño, José M Pingarrón
Amylin (the islet amyloid polypeptide) is a hormone related to adiposity, hunger and satiety. It is co-secreted with insulin from pancreatic B-cells. An amperometric immunosensor is presented here for the determination of amylin. It is making use of a screen printed carbon electrode (SPCE) functionalized with electropolymerized poly(pyrrole propionic acid) (pPPA) with abundant carboxyl groups that facilitate covalent binding of antibody against amylin. A competitive immunoassay was implemented using biotinylated amylin and streptavidin labeled with horse radish peroxidase (HRP-Strept) as the enzymatic tracer...
June 9, 2018: Mikrochimica Acta
Habib Bagheri, Faranak Manshaei, Omid Rezvani
Three-dimensional (3D) polyamide scaffolds were fabricated by applying a solvent bath as the collecting element. Electrospun nanofibers were immersed into the solvent bath to give a material with a laminated 3D texture. In parallel, 2D nanofibers were synthesized and utilized as microextractive phases in a needle trap device to compare the capabilities of 2D and 3D materials in terms of headspace extraction of various chlorobenzenes (chlorobenzene, 1,2-dichlorobenzene, 1,4-dichlorobenzene, 1,2,4-trichlorobenzene and 1,2,3,4-tetrachlorobenzene)...
June 8, 2018: Mikrochimica Acta
Lanlan Wei, Yuan Song, Ping Liu, Xuejun Kang
Polystyrene nanofibers were coated with copper nanoparticles (CuNPs) by a combination of electrospinning and in-situ reduction of Cu(II) using sodium borohydride as the reductant. The CuNPs on the nanofibers were characterized by energy dispersive spectrometry, scanning electron microscopy and transmission electron microscopy. A cartridge was packed with the nanofibers which then were activated with methanol and water. Glutathione (GSH) is found to quantitatively adsorbed by the packed cartridge at pH 3.0, and then can be desorbed with aqueous 2-mercaptoethanol and detected, after derivatization with ortho-phthalaldehyde, via high performance liquid chromatography with fluorometric detection...
June 8, 2018: Mikrochimica Acta
Mehdi Baghayeri, Reza Ansari, Marzieh Nodehi, Iman Razavipanah, Hojat Veisi
The present study describes an electrochemical aptamer-based method for the determination of bisphenol A (BPA). It is making use of gold nanoparticles (AuNPs) immobilized on a conjugate between multiwalled carbon nanotubes and thiol-functionalized magnetic nanoparticles (MWCNT/Fe3 O4 -SH) that are modified with an aptamer. The nanocomposite was characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, elemental mapping analysis and energy dispersive X-ray diffraction...
June 7, 2018: Mikrochimica Acta
Chongmei Sun, Fangzheng Yuan, Huihui Li, Xia Wu
A nanoprobe was developed for the fluorometric determination of the neurotransmitter dopamine (DA). It is based on the synergistic enhancement action of citrate and gold nanoparticles (AuNPs) on the luminescence of Tb(III). AuNPs serve as substrates of surface enhanced fluorescence (SEF). Citrate, in turn, acts as a spacer for the SEF effect, a co-ligand of Tb(III) complex, and a recognizing component for DA. The synergistic action of citrate and AuNPs significantly increases the intrinsic green fluorescence of Tb(III) (best measured at excitation/emission peaks of 300/547 nm)...
June 6, 2018: Mikrochimica Acta
Bingyu Zhang, Xiaoyun Lei, Lijun Deng, Minsheng Li, Sicong Yao, Xiaoping Wu
An ionic liquid hybrid monolithic capillary column was prepared within 7 min via photoinitiated free-radical polymerization of an ionic liquid monomer (1-butyl-3-vinylimidazolium-bis[(trifluoromethyl)sulfonyl]imide); VBIMNTF2 ) and a methacryl substituted polyhedral oligomeric silsesquioxane (POSS-MA) acting as a cross-linker. The effects of composition of prepolymerization solution and initiation time on the porous structure and electroosmotic flow (EOF) of monolithic column were investigated. The hybrid monolith was characterized by scanning electron microscopy and FTIR...
June 6, 2018: Mikrochimica Acta
Veerappan Nagarajan, Arunachalam Thayumanavan
Spinel CdFe2 O4 thin films were synthesized by spray pyrolysis. The structural probe studies confirmed the multicrystalline nature of the films with their spinel structure. The crystallites have sizes between 13 and 37 nm and island morphology. The energy dispersive spectroscopy reveals the presence of iron, oxygen and cadmium in the film. The room temperature electrical resistance of the thin film, best measured at a voltage of 10 V, decreases rapidly if it is exposed to vapors of formaldehyde or ethanol...
June 6, 2018: Mikrochimica Acta
Siyuan Tan, Jundong Wang, Qiang Han, Qionglin Liang, Mingyu Ding
A novel polydopamine coated three-dimensional porous graphene aerogel sorbent carrying immobilized titanium(IV) ions (denoted as Ti4+ @PDA@GA) was fabricated without using an organic solvent. The material is shown to be a viable carbon foam type of monolithic sorbent for selective lab-in-syringe enrichment of phosphoproteins and phosphopeptides. The phosphoproteins can be separated from a sample by aspiration and then bind to the sorbent. The analytes then can be dispensed within 5 min. The weight percent of titanium in the monolith typically is 14%, and the absorption capacities for the model proteins β-casein and κ-casein are 1300 and 1345 mg g-1 , respectively...
June 6, 2018: Mikrochimica Acta
Yong Wang, Wei Cao, Luyao Wang, Qianfen Zhuang, Yongnian Ni
A metal organic framework (MOF) of the type copper(II)-1,3,5-benzenetricarboxylic acid (Cu-BTC) was electrodeposited on electroreduced graphene oxide (ERGO) placed on a glassy carbon electrode (GCE). The modified GCE was used for highly sensitive electrochemical determination of 2,4,6-trinitrophenol (TNP). The fabrication process of the modified electrode was characterized by scanning electron microscopy and electrochemical impedance spectroscopy. Differential pulse voltammetry (DPV) demonstrates that the Cu-BTC/ERGO/GCE gives stronger signals for TNP reduction than Cu-BTC/GCE or ERGO/GCE alone...
June 4, 2018: Mikrochimica Acta
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"