Glassy carbon electrodes (GCE) were sequentially modified by cysteamine-capped gold nanoparticles (AuNp@cysteamine) and PAMAM dendrimers generation 4.5 bearing 128-COOH peripheral groups (GCE/AuNp@cysteamine/PAMAM), in order to explore their capabilities as electrochemical detectors of uric acid (UA) in human serum samples at pH 2. The results showed that concentrations of UA detected by cyclic voltammetry with GCE/AuNp@cysteamine/PAMAM were comparable (deviation <±10%; limits of detection (LOD) and quantification (LOQ) were 1.7×10(-4) and 5.8×10(-4) mg dL(-1), respectively) to those concentrations obtained using the uricase-based enzymatic-colorimetric method. It was also observed that the presence of dendrimers in the GCE/AuNp@cysteamine/PAMAM system minimizes ascorbic acid (AA) interference during UA oxidation, thus improving the electrocatalytic activity of the gold nanoparticles.
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http://dx.doi.org/10.1016/j.aca.2013.12.025 | DOI Listing |
Dalton Trans
January 2025
Department of Chemistry and the MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
Appropriately designed catalysts help to minimise the energy required to convert the energy-poor feedstock HO into energy-rich molecular H. Herein, two families of pyridazine-based cryptates, mononuclear [MLi](BF) and mixed metal dinuclear [MCuLi](BF) (M = Fe, Co, Cu or Zn; Li is the Schiff base cryptand made by 2 : 3 condensation of tris(2-aminoethyl)amine and 3,6-diformylpyridazine), are investigated as potential electrocatalysts for the hydrogen evolution reaction (HER) in MeCN with acetic acid as the proton source. The synthesis and structures of a new mixed metal cryptate, [ZnCuLi](BF), and the tetrafluoroborate analogue of the previously reported perchlorate salt of the mono-zinc cryptate, [ZnLi](BF)·0.
View Article and Find Full Text PDFBioelectrochemistry
January 2025
Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, National University of Science and Technology Politehnica Bucharest, 1-7 Gheorghe Polizu St., 011061 Bucharest, Romania. Electronic address:
Herein, we present an efficient approach for developing electrochemical aptasensing interfaces, by "click" postfunctionalization of phenylethynyl-grafted glassy carbon substrates with mixed monolayers containing biorecognition elements and phosphorylcholine zwitterionic groups. Typically, controlling the composition of multicomponent surface layers by grafting from a mixture of aryldiazonium salts is challenging due to differences in their chemical reactivity. Our approach circumvents this issue by employing the electrochemical reduction of a single aryldiazonium salt containing a silyl-protected alkyne group followed by deprotection, to create phenylethynyl monolayers which can subsequently accommodate the concurrent immobilization of bioreceptors and zwitterionic groups through "click" postfunctionalization.
View Article and Find Full Text PDFACS Sens
January 2025
Department of Chemistry, Burke Laboratories, Dartmouth College, 41 College St., Hanover, New Hampshire 03755, United States.
This paper describes the first use of conductive metal-organic frameworks as the active material in the electrochemical detection of nitric oxide in aqueous solution. Four hexahydroxytriphenylene (HHTP)-based MOFs linked with first-row transition metal nodes (M = Co, Ni, Cu, Zn) were compared as thin-film working electrodes for promoting oxidation of NO using voltammetric and amperometric techniques. Cu- and Ni-linked MOF analogs provided signal enhancement of 5- to 7-fold over a control glassy carbon electrode (SA = 6.
View Article and Find Full Text PDFAnal Methods
January 2025
Department of Nutrition and Dietetics, Faculty of Health Sciences, Hasan Kalyoncu University, Gazi-antep, 27000, Turkey.
In the present study, a novel voltammetric sensor based on a boron-doped copper oxide/graphene (B-CuO-Gr) nanocomposite and molecularly imprinted polymer (MIP) was developed for the detection of paclobutrazol (PAC) in apple and orange juice samples. The B-CuO-Gr nanocomposite was prepared using sol-gel and calcination methods. After modifying glassy carbon electrodes with the B-CuO-Gr nanocomposite, PAC-imprinted electrodes were prepared in the presence of 100.
View Article and Find Full Text PDFInorg Chem
January 2025
MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China.
A novel antimonotungstate (AT)-based heterometallic framework {[Er(HO)][Fe(Hpdc)(B-β-SbWO)]}·50HO (, Hpdc = pyridine-2,5-dicarboxylic acid) was obtained through a synergistic strategy of in situ-generated transition-metal-encapsulated polyoxometalate (POM) building units and the substitution reaction. Its structural unit is composed of a tetra-Fe-substituted Krebs-type [Fe(Hpdc)(B-β-SbWO)] subunit and two [Er(HO)] cations. This subunit can be regarded as a product of carboxylic oxygen atoms of Hpdc ligands replacing active water ligands in the [Fe(HO)(B-β-SbWO)] species.
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