Showing papers by "Hui Wei published in 2007"
TL;DR: A simple and sensitive aptamer-based colorimetric sensing of protein (alpha-thrombin in this work) using unmodified gold nanoparticle probes is described.
450 citations
TL;DR: SERS aptasensors for protein recognition based on Au nanoparticles labeled with aptamers and Raman reporters have been developed, which opens a new way forprotein recognition of high sensitivity and selectivity.
147 citations
TL;DR: An aptamer-based method for the sensitive detection of proteins by a label-free fluorescing molecular switch (ethidium bromide) shows promising potential in making protein assay simple and economical.
116 citations
TL;DR: In this article, a simple and effective supramolecular route for facile synthesis of submicrometer-scale, hierarchically self-assembled spherical colloidal particles of adenine−gold(III) hybrid materials at room temperature was reported.
Abstract: We report a simple and effective supramolecular route for facile synthesis of submicrometer-scale, hierarchically self-assembled spherical colloidal particles of adenine−gold(III) hybrid materials at room temperature. Simple mixture of the precursor aqueous solutions of adenine and HAuCl4 at room temperature could result in spontaneous formation of the hybrid colloidal particles. Optimization of the experimental conditions could yield uniform-sized, self-assembled products at 1:4 molar ration of adenine to HAuCl4. Transmission electron microscopy results reveal the formation of hierarchical self-assembled structure of the as-prepared colloidal particles. Concentration dependence, ratio dependence, time dependence, and kinetic measurements have been investigated. Moreover, spectroscopic evidence [i.e., Fourier transform infrared (FTIR) and UV−vis spectra and wide-angle X-ray scattering data] of the interaction motives causing the formation of the colloidal particles is also presented. The as-prepared nucle...
111 citations
TL;DR: An effective electrochemiluminescence (ECL) sensor based on PSP with carbon nanotube (CNTs) composite film was developed and the results indicated the ECL intensity produced was over 3-fold compared with that of the pure PSP film due to the electrocatalytic activity of the CNTs.
Abstract: Herein, homogenously partial sulfonation of polystyrene (PSP) was performed. An effective electrochemiluminescence (ECL) sensor based on PSP with carbon nanotube (CNTs) composite film was developed. Cyclic voltammetry and electrochemical impendence spectroscopy were applied to characterize this composite film. The PSP was used as an immobilization matrix to entrap the ECL reagent Ru(bpy)32+ due to the electrostatic interactions between sulfonic acid groups and Ru(bpy)32+ cations. The introduction of CNTs into PSP acted not only as a conducting pathway to accelerate the electron transfer but also as a proper matrix to immobilize Ru(bpy)32+ on the electrode by hydrophobic interaction. Furthermore, the results indicated the ECL intensity produced at this composite film was over 3-fold compared with that of the pure PSP film due to the electrocatalytic activity of the CNTs. Such a sensor was verified by the sensitive determinations of 2-(dibutylamino)ethanol and tripropylamine.
76 citations
TL;DR: Label free electrochemiluminescence (ECL) DNA detection based on catalytic guanine and adenine bases oxidation using tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)(3)(2+)] modified glassy carbon (GC) electrode was demonstrated in this article.
70 citations
TL;DR: A sensitive electrochemical aptasensor for adenosine based on electrochemical impedance spectroscopy measurement is reported, which gives not only a label-free but also a reusable platform to make the detection of small molecules simple and convenient.
68 citations
TL;DR: A novel electrochemical H2O2 biosensor was constructed by embedding horseradish peroxide in a 1-butyl-3-methylimidazolium tetrafluoroborate doped DNA network casting on a gold electrode to provide both a biocompatible microenvironment for enzymes to keep their good bioactivity and an effective pathway of electron transfer between the redox center of enzymes, H2 O2 and the electrode surface.
Abstract: A novel electrochemical H2O2 biosensor was constructed by embedding horseradish peroxide (HRP) in a 1-butyl-3-methylimidazolium tetrafluoroborate doped DNA network casting on a gold electrode. The HRP entrapped in the composite system displayed good electrocatalytic response to the reduction of H2O2. The composite system could provide both a biocompatible microenvironment for enzymes to keep their good bioactivity and an effective pathway of electron transfer between the redox center of enzymes, H2O2 and the electrode surface. Voltammetric and time-based amperometric techniques were applied to characterize the properties of the biosensor. The effects of pH and potential on the amperometric response to H2O2 were studied. The biosensor can achieve 95% of the steady-state current within 2 s response to H2O2. The detection limit of the biosensor was 3.5 μM, and linear range was from 0.01 to 7.4 mM. Moreover, the biosensor exhibited good sensitivity and stability. The film can also be readily used as an immobilization matrix to entrap other enzymes to prepare other similar biosensors.
58 citations
TL;DR: In this article, the preparation of silver nanoparticles using nucleobase adenine as protecting agent through the in situ chemical reduction of AgNO3 with NaBH4 in an aqueous medium at room temperature was described.
Abstract: We describe herein the preparation of silver nanoparticles (AgNPs) using nucleobase adenine as protecting agent through the in situ chemical reduction of AgNO3 with NaBH4 in an aqueous medium at room temperature. As-prepared AgNPs were characterized by UV-visible spectra, transmission electron microscopy and x-ray photoelectron spectroscopy. All these data confirmed the formation of AgNPs. On the basis of electrostatic interactions between as-prepared AgNPs and anionic polyelectrolyte poly(sodium 4-styrenesulfonate) (PSS), we successfully fabricated (PSS/AgNP)n (n = 0-9) multilayers on a 3-mercaptopropyltrimethoxysilane/AgNP functionalized indium tin oxide (ITO) substrate via the layer-by-layer self-assembly technique and characterized as-formed multilayers with UV-visible spectra. Furthermore, these ITO substrates coated with multilayers of different thickness were investigated as surface-enhanced Raman scattering (SERS)-active substrates using p-aminothiophenol as a probe molecule, implying that these multilayers substrates may be promising for a new type of SERS-active substrate.
44 citations
TL;DR: The results indicated that the MCM-41-modified IL-CPE had more open structures to allow faster diffusion of Ru(bpy)(3)(2+) and that the ionic liquid also acted as a conducting bridge to connect TPrA with Ru(2,2'-bipyridyl)ruthenium(II) sites immobilized in the electrode, resulting in a higher ECL intensity.
Abstract: The electrochemiluminescence (ECL) of tris(2,2′-bipyridyl)ruthenium(II) [Ru(bpy)32+] ion-exchanged in the sulfonic-functionalized MCM-41 silicas was developed with tripropylamine (TPrA) as a co-reactant in a carbon paste electrode (CPE) using a room temperature ionic liquid (IL) as a binder. The sulfonic-functionalized silicas MCM-41 were used for preparing an ECL sensor by the electrostatic interactions between Ru(bpy)32+ cations and sulfonic acid groups. We used the IL as a binder to construct the CPE (IL-CPE) to replace the traditional binder of the CPE (T-CPE) – silicone oil. The results indicated that the MCM-41-modified IL-CPE had more open structures to allow faster diffusion of Ru(bpy)32+ and that the ionic liquid also acted as a conducting bridge to connect TPrA with Ru(bpy)32+ sites immobilized in the electrode, resulting in a higher ECL intensity compared with the MCM-41-modified T-CPE. Herein, the detection limit for TPrA of the MCM-41-modified IL-CPE was 7.2 nM, which was two orders of magnitude lower than that observed at the T-CPE. When this new sensor was used in flow injection analysis (FIA), the MCM-41-modified IL-CPE ECL sensor also showed good reproducibility. Furthermore, the sensor could also be renewed easily by mechanical polishing whenever needed.
43 citations
TL;DR: In this article, the electrochemiluminescence (ECL) in the S2O82- system occurs under conventional cyclic voltammetry, when the Pt working electrode was coated with Cd elementary substance.
TL;DR: In this paper, the synthesis of submicrometre scale single-crystalline gold plates of nanometre thickness in the presence of nucleobase guanine through chemical reduction of HAuCl4 was investigated.
Abstract: Synthesis of submicrometre scale single-crystalline gold plates of nanometre thickness in the presence of nucleobase guanine through chemical reduction of HAuCl4 was investigated. The elemental composition of the as-prepared gold nanoplates was estimated using energy-dispersive x-ray spectroscopy. The as-prepared gold plates were composed of essentially (111) lattice planes, as revealed by both x-ray diffraction (XRD) and transmission electron microscopy (TEM) results. It was found that the molar ratio of HAuCl4 to guanine played a very important role in the formation of gold nanoplates. Gold nanoplates could be produced at a molar ratio of [HAuCl4]/[guanine] = 50:1 while only smaller gold spherical nanoparticles were obtained at molar ratios of [HAuCl4]/[guanine]≤20:1. A possible growth mechanism of the as-prepared gold nanoplates is proposed and discussed. The results and conclusion presented in this work may be valuable for our further understanding of the roles of precursor ligands in the control of nanoparticles aggregation states and the preparation of shape-controlled nanoparticles.
TL;DR: In this paper, an approach was reported to synthesize silica hybridized ruthenium bipyridyl complex through amidation reaction by covalent attachment of bis(bipyridis)-4,4′-dicarboxy-2,2′-branchy-ruthensium to (3-aminopropyl)-triethoxy-silane.
Abstract: An approach was reported to synthesize silica hybridized ruthenium bipyridyl complex through amidation reaction by covalent attachment of bis(bipyridyl)-4,4′-dicarboxy-2,2′-bipyridyl-ruthenium to (3-aminopropyl)-triethoxy- silane. The hybrid complex then was gelatinized through acid catalytic hydrolysis method and a sol-gel modified indium tin oxide electrode was prepared via spin coating technique. As prepared indium tin oxide electrode possesses good stability therein with excellent electrochemiluminescence behavior.