Novel self-assembled dipeptide-gold nanoparticle (DP-AuNP) hybrid microspheres with a hollow structure have been prepared in aqueous solution by a simple one-step method. Diphenylalanine (FF) dipeptide was used as a precursor to form simultaneously peptide spheres and a reducing agent to reduce gold ions to gold nanoparticles in water at 60°C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that formed AuNPs were localized both inside and on the surface of the dipeptide spheres. Horseradish peroxidase (HRP) as a model enzyme was further immobilized on the dipeptide-AuNP hybrid spheres to construct a mediate H2O2 amperometric biosensor. UV-vis spectroscopy showed that the immobilized HRP retained its original structure. Cyclic voltammetry characterization demonstrated that the HRP/dipeptide-AuNP hybrid spheres modified glassy carbon electrode showed high electrocatalytic activity to H2O2. The proposed biosensor exhibited a wide linear response in the range from 5.0×10(-7) to 9.7×10(-4)M with a high sensitivity of 28.3µAmM(-1). A low detection limit of 1.0×10(-7)M was estimated at S/N=3. In addition, the biosensor possessed satisfactory reproducibility and long-term stability. These results indicated that the dipeptide-AuNP hybrid sphere is a promising matrix for application in the fabrication of electrochemical biosensors due to its excellent biocompatibility and good charge-transfer ability.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.bios.2014.11.029 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Western University, Chemistry, 1151 Richmond Street, N6A3K7, London, CANADA.
This work addresses fundamental questions that deepen our understanding of secondary coordination sphere effects on carbon dioxide (CO2) reduction using derivatized hydride analogues of the type, [Cp*Fe(diphosphine)H] (Cp* = C5Me5-) - a well-studied family of organometallic complex - as models. More precisely, we describe the general reactivity of [(Cp*-BR2)Fe(diphosphine)H], which contains an intramolecularly positioned Lewis acid, and its cooperative reactivity with CO2. Control experiments underscore the critical nature of borane incorporation for CO2 to reduced products, a reaction that does not occur for unfunctionalized [Cp*Fe(diphosphine)H]).
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, FI-80100, Joensuu, Finland.
Activation of rac-MeSi(η-Ind)ZrMe (SBIZrMe) and sheet models for MAO, (MeAlO)(MeAl) (6,4), (MeAlO)(MeAl) (7,5), and (MeAlO)(MeAl) (26,9) was studied DFT. These activators can reversibly form an outer-sphere ion-pair (OSIP) [SBIZrMeAlMe] [(MeAlO)(MeAl)Me] 3 ([,] = [7,4]and [26,8]) or a contact ion-pair (CIP) SBIZrMe-μ-Me-6,4 (2b) from SBIZrMe. Dissociation of MeAl from 3 to form CIP SBIZrMe-μ-Me-, (2) is generally unfavourable but reversible in toluene continuum.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Physics, School of Advanced Sciences, Vellore Institute of Technology (VIT) Chennai, Vandalur - Kelambakkam Road, Chennai 600127, India.
Talanta
December 2024
College of Chemistry and Molecular Engineering. Qingdao University of Science and Technology, Qingdao, 266042, China. Electronic address:
In this work, a new dual-signal fluorescence strategy based on nano-gold molecular beacon (MB) and in-situ generated silver nano-clusters (NCs) coupled with multiple amplification technique was developed for sensitive detection of miRNA (let-7b). miRNA can recognize both hairpin probe (HP) and auxiliary DNA, inducing dual-cycle amplification-process to release plenty of DNA S2. As the report probe carboxyfluorescein (FAM) was modified on Au nanoparticles (AuNPs), the fluorescent signal was quenched due to the fluorescence resonance energy transfer (FRET).
View Article and Find Full Text PDFNanotechnology
December 2024
IMDEA Materials Institute, C/ Eric Kandel 2, Getafe, Madrid, 28906, SPAIN.
Although Mg-Li dual metal-ion batteries are proposed as a superior system that unite safety of Mg-batteries and performance of Li-ion based systems, its practical implantation is limited due to the lack of reliable high performance cathodes. Herein, we report a high-performance Mg-Li dual metal-ion battery system based on highly pseudocapacitive hierarchical TiO2-B nanosheet assembled spheres (NS) cathode. This 2D cathode displayed exceptional pseudocapacitance (a maximum of 93%) specific capacity (303 mAh/g at 25 mA/g), rate performance (210 mAh/g at 1A/g), consistent cycling (retain ~100% capacity for 3000 cycles at 1A/g), coulombic efficiency (nearly 100%) and fast-charging (~12.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!