Wei Ma

Beijing University of Technology | Bei Gong Da · Department of Geography

Few-layered molybdenum chalcogenide (MoS2) has attracted considerable attention due to its defect-rich structure and active edge sites, triggering distinctive electrocatalysis and magnetism properties. Quantifying the intrinsic properties of a single entity is of paramount importance for clarifying the structure-activity correlation. Here, the intr...

Understanding the basic physicochemical properties of gas molecules confined within nanobubbles is of fundamental importance for chemical and biological processes. Here, we successfully monitored the nanobubble-confined electrochemical behaviors of single platinum nanoparticles (PtNPs) at a carbon fiber ultramicroelectrode in HClO4 and H2O2 solutio...

The potential distribution at the electrode interface is a core factor in electrochemistry, and it is usually treated by the classic Gouy-Chapman-Stern (G-C-S) model. Yet the G-C-S model is not applicable to nanosized particles collision electrochemistry as it describes steady-state electrode potential distribution. Additionally, the effect of sing...

Understanding the basic physicochemical properties of gas molecules confined within nanobubbles is of fundamental importance for chemical and biological process. Here we successfully monitored the nanobubble-confined electrochemical behaviors of single platinum nanoparticles (PtNPs) at a carbon fiber ultramicroelectrode in HClO4 and H2O2 solution....

Development of simple, robust, and reliable detection strategy of disease biomarkers holds tremendous promise for early clinical diagnosis and prognosis of diseases. In this work, through combining a silver nanoparticle (AgNP) linked immunoassay and aggregation induced emission (AIE)-based fluorogenic Ag⁺ probe, we developed a silver-amplified fluo...

Current strategies for the detection of disease biomarkers often require enzymatic assays that may have limited sensitivity due to the inferior stability and vulnerable catalytic activity of the enzyme. A new enzyme-free amplification method for identifying suitable biomarkers is necessary to lower the limit of detection and improve many critical d...

With the development of new instruments and methodologies, the highly dynamic behaviors of nanoparticle at the liquid-solid interface have been studied. However, the dynamic nature of the electrochemical behavior of individual nanoparticles on the electrode interface is still poorly understood. Here, we generalize scaling relations to predict nanop...

Ensemble averaging measurements obscure the link between the electrochemical performance and the specific properties of an individual because of the interplay of inhomogeneity and heterogeneity. Nanocollision electrochemistry has attracted increasing interest because of its extremely high sensitivity, revealing the intrinsic properties of individua...

Understanding the photoinduced electron-transfer process is of paramount importance for realizing efficient solar energy conversion. It is rather difficult to clarify the link between the specific properties and the photoelectrochemical performance of an individual component in an ensemble system because data are usually presented as averages becau...

We reported a novel method for the first time to real-time monitor the redox behaviors of single Ag nanoparticles (NPs) at a Au ultramicroelectrode between oxidizing and reducing pulse potentials using nanocollision electrochemical method. At fast pulse potentials, the instantaneous anodic–cathodic current transients of a single AgNP were observed...

Gold nanoparticles (AuNPs) have been demonstrated to serve as effective nanomaterial‐based enzyme mimetics (nanozymes) for a number of enzymatic reactions under mild conditions. The intrinsic glucose oxidase and peroxidase activities of single AuNPs and Ag–Au nanohybrids, respectively, were investigated by single NP collision electrochemical measur...

Gold nanoparticles (AuNPs) have been demonstrated to serve as the effective nanomaterial‐based enzyme mimetics (nanozymes) for a number of enzymatic reactions under mild conditions. Intrigued by single NP collision electrochemical measurements, we investigated the intrinsic catalytic activities of single AuNPs and Ag‐Au nanohybrids as glucose oxida...

Gold nanoparticles (AuNPs) have been demonstrated to serve as effective nanomaterial‐based enzyme mimetics (nanozymes) for a number of enzymatic reactions under mild conditions. The intrinsic glucose oxidase and peroxidase activities of single AuNPs and Ag–Au nanohybrids, respectively, were investigated by single NP collision electrochemical measur...

Understanding the real nature of the intrinsic electrocatalytic performance of counter electrode is crucial for realizing high conversion efficiency of solar energy in photoelectric devices. However, owing to the average effects, a thorough insight into such electrocatalytic process remains challenging in ensemble measurements. Here, we realized th...

Quantifying the photoinduced electron transfer properties of single entity is of paramount importance for clarifying the link between the photoelectrochemical performance and the specific properties of individual. Here, we successfully monitored the photoelectrochemical behavior of single dye-sensitized ZnO entity on a Au ultramicroelectrode with di...

We presented an ultrasensitive photoelectrochemical method for achieving the real-time detection of single nanoparticle collision events. Using a newly developed micrometre-thick nanoparticulate TiO2-filmed Au ultramicroelectrode (TiO2@Au UME), a transient, sub-millisecond photocurrent was observed for an individual N719-tagged TiO2 (N719@TiO2) nan...

Steady-state cyclic voltammetry has several advantages that make it extremely useful for characterization of ultramicroelectrodes, such as rapid electrode performance assessment and size determination. However, due to the nanoscale size effect, the slight variations in geometry of the nanoelectrodes can lead to significant perturbations in its perf...

Detection of biomarkers is extremely important for the early diagnosis of diseases. Here, we developed an easy and highly sensitive fluorescence detection system for the determination of biomarkers by combining the rapid separation of magnetic beads and silver nanoparticles labeled antibodies. An ultrasensitive silver ions fluorescence probe 3', 6'...

Single nanoparticle (NP) electrochemical measurements are widely described, both theoretically and experimentally, as they enable visualization of the electrochemical signal of a single NP that is masked in ensemble measurements. However, investigating the behavior of individual NPs using electrochemical signals remains a significant challenge. Her...

Changes in the optical properties of single gold nanorods during electrocatalytic oxidation of glucose in alkaline media are monitored in real-time by single-nanoparticle dark-field spectroelectrochemistry. The spectral scattering characteristics under dynamic potential scan conditions are closely related to the electrochemical processes, and the e...

Studying chemical reactions at the nanoscale level could aid to better understand and control reaction processes. In this paper, the redox reaction between hydroquinone and Ag+ via gold nanoparticles as a suitable surface was taken as an example, where its thermochemical values were computed by using density functional theory (DFT) methods with 6-3...

Electrocatalysis of molecules is a hot research in biological and energy-related chemistry. Here, we develop a new system to study the elec-trocatalytic efficiency of single catechol molecule for NADH oxidation at micro-interface between nanoparticles and ultramicroelectrodes (UMEs). The proposed system are composed of gold nanoparticles (AuNPs) fu...

Determination of disease biomarkers in clinical samples is of crucial significance for disease monitoring and public health. The dominating format is enzyme-linked immunosorbent assay (ELISA), which subtly exploits both the antigen-antibody reaction and biocatalytic property of enzymes. Although enzymes play an important role in this platform, they...

Supplementary information and figures.

A novel redox-mediated chromogenic reaction was demonstrated based on the reaction between HAuCl4 and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), which generate various color responses from red to green in the resulting solutions. Various redox substance could be used to mediate the reaction and trigger a distinct color response....

We demonstrate reversible photoisomerizaton of azobenzene molecules on a single gold nanoparticle surface with alternating UV and visible irradiation, which is monitored by Plasmon Resonance Rayleigh Scattering spectroscopy and stimulated by discrete-dipole approximation method.

Dopamine (DA) quinone-induced dopaminergic neurotoxicity is known to occur due to the interaction process between the DA quinone and the cysteine (Cys) residue, and it may play an important a role in pathological processes associated with neurodegeneration. In this study, we monitored the interaction process of DA to form DA quinone and the subsequ...

Intramolecular electronic communications of molecular wires play a crucial role for developing molecular devices. In the present work, we describe different degrees of intramolecular electronic communications in the redox processes of three ubiquinone-based biomolecular wires (Bis-CoQ0s) evaluated by electrochemistry and Density Functional Theory (...

Here, we reported a strategy based plasmonic enzyme-linked immunosorbent assay (ELISA) using alcohol dehydrogenase-catalyzed gold nanoparticle seed-mediated growth to serve as a colorimetric signal generation method for detecting disease biomarkers with the naked eye. This system possesses the advantages of outstanding robustness, sensitivity and u...

Here, polydopamine derivative monolayer was generated by electro-polymerization of thiol dopamine derivatives modified on gold electrode, and the adhesion of polydopamine made it being a platform for secondary reaction. The influence of pH on the formation of polydopamine derivative was investigated. Horseradish peroxidase (HRP) was adhered on the...

Real-time optical monitoring of the electron-transfer process was achieved and modulated on individual gold nanoparticles functionalized with graphene. We found that charge accumulation on single gold nanorods (GNRs) depends on the rate of Faradaic reaction, which is synchronized with double-layer charging.

The morphological characteristics of metal nanoparticles, particularly the shape, play an essential role in the optical, physical and chemical properties. In this work, we reported a transverse etching process to investigate the morphological variations of single gold nanorods (GNRs). Dark-field microscopy and Rayleigh scattering spectroscopy were...

Here, we describe a novel "switch-on" biosensor based on quinonyl glycosides functionalized quantum dots (QDs) for the specific targeting and imaging of transmembrane glycoprotein receptors on the surface of cancer cells. The design of the quinonyl glycosides lies in that the quinone moiety serves as a quencher of QDs and the glycoside moiety as a...

The lacunary polyoxometalate (LPOM) encapsulated into the hexagonal mesoporous silica matrix materials were successfully prepared via a directly synthesis method by adjusting pH of the preparation system from 2.0 to 6.0. The materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption–desorption measurem...

In this work, we report the features of size-selective fragmentation of gold nanoparticles (AuNPs) by thioanisole. Large particles are observed as prone to easier fragmentation than the smaller ones, the key-role being played by the effect of surface charge and surface coverage.

Quinones/hydroquinones (Q/HQ) are a class of prototypical redox molecules that play a variety of vital roles in biology, particularly in electron transfer and energy conservation systems. Biointerfaces supported on solid substrates or nanomaterials are widely used as biomimetic platforms that connect biological materials with artificial interfaces....

A method based on plasmon resonance Rayleigh scattering (PRRS) spectroscopy and dark-field microscopy (DFM) was established for the real-time monitoring of a click reaction at the single-nanoparticle level. Click reactions on the surface of single gold nanoparticles (GNPs) result in interparticle coupling, which leads to a red-shift of the λmax (Δλ...

Scientific Reports 3, Article number: 1537 10.1038/srep01537 (2013); Published: March252013; Updated: April182013 The authors have noticed that Figure 1 was published incorrectly in the original version of this Article. The correct Figure 1 appears below. Figure 1 Schematic of ubiquinone-CdSe/ZnS QDs as redox fluorescence biosensor for Parkinson...

Quantum dots (QDs) have attracted increasing interest in bioimaging and sensing. Here, we report a biosensor of complex I using ubiquinone-terminated disulphides with different alkyl spacers (QnNS, n = 2, 5 and 10) as surface-capping ligands to functionalise CdSe/ZnS QDs. The enhancement or quenching of the QD bioconjugates fluorescence changes as...

Ubiquinone-quantum dot bioconjugates for in vitro and intracellular complex I sensing

We report the spontaneous fragmentation of gold nanoparticles (AuNPs) induced, in aqueous solution at room temperature, by thiol derivative of ubiquinone, which involves the energetic electron injection from thiol-ubiquinone to the gold nanoparticles.

Here we report a protocol to investigate the electron-transfer processes of redox-active biomolecules in biological membranes by electrochemistry using biomimetic hybrid bilayer membranes (HBMs) assembled on gold electrodes. Redox-active head groups, such as the ubiquinone moiety, are embedded in HBMs that contain target molecules, e.g., nicotinami...

We report the spontaneous fragmentation of gold nanoparticles (AuNPs) induced, in aqueous solution at room temperature, by thiol derivative of ubiquinone, which involves the energetic electron injection from thiol-ubiquinone to the gold nanoparticles.

The ordered mesoporous MCM-41 materials incorporated with transition metal substituted polyoxometalate (PW11O39M1)5− (designated as M1–POM, M1 = Ni2+, Co2+ or Cu2+) were synthesized via an original direct synthesis method. The samples were characterized by XRF, XRD, FT-IR, HRTEM, SEM and N2 adsorption isotherm techniques. The results show that M1–P...

Mesoporous silica pillared clay (SPC) incorporated with tungstophosphoric acid (HPW) has been synthesized via in situ introducing P and W source in the acidic suspension of the clay interlayer template during the formation of the silica pillared clay. The samples were characterized by XRD, XRF, FT-IR, TG-DTA, N(2) adsorption-desorption, and SEM tec...

Light in the dark: Metal nanoparticles (M=Ag(0) , Au(0) , or Cu(0) ) were electrodeposited onto ion-channel pores of a stable protein 1 membrane. The metal nanoparticles were implemented for detection of antigen-antibody binding events at the single-particle level using dark field microscopy and plasmon resonance Rayleigh scattering.

The growth of metal nanoparticles on ion-channel pores of a stable protein 1 (SP1) membrane is monitored in situ by dark field microscopy and plasmon resonance Rayleigh scattering. In their Communication (DOI: 10.1002/anie.201106482), Y.-T. Long and co-workers describe the electrodeposition process of single nanoparticles in the core of an SP1 temp...

Well-ordered hexagonal mesoporous silicate (HMS) materials with various contents of phosphotungstic acid (HPW) were synthesized via an original direct synthesis method. The characterization results show that the samples have regular fingerprint-like mesopores and spherical morphology. Compared with the conventional wet impregnation method, the samp...

The ordered mesoporous MCM-41 materials incorporated with lacunary polyoxometalate were prepared via an original direct synthesis method. As the control, the samples with similar lacunary polyoxometalate loadings were also prepared by impregnation of MCM-41. The prepared samples were characterized by XRF, XRD, FT-IR, Raman spectra, HRTEM, SEM, N(2)...

Here, we report the reversible interconversion between NADH and NAD(+) at a low overpotential, which is in part mediated by ubiquinone embedded in a biomimetic membrane to mimic the initial stages of respiration. This system can be used as a platform to examine biologically relevant electroactive molecules embedded in a natural membrane environment...

Quinones are a group of potent antineoplastic agents. Here we described effective and facile routes to synthesize a series of ubiquinone analogues (UQAs). These unique compounds have been investigated by electrochemistry and in situ UV–vis spectroelectrochemistry to explore their electron-transfer processes and radical properties in aprotic media....

Quantum dots (QDs) have been widely used for fluorescent imaging in cells. In particular, surface functionalized QDs are of interest, since they possess the ability to recognize and detect the analytes in the surrounding nanoscale environment based on electron and hole transfer between the analytes and the QDs. Here we demonstrate that fluorescence...

Coenzyme Qs, which are distributed in virtually all living cell membranes, shuttle electrons in the respiratory chain using their redox quinonyl group. In their Full paper on page 1064 ff., Y.-T. Long et al. report a newly synthesized methylene-bridged bis-Coenzyme Q0, bis(2,3-dimethoxy-5-methyl-l,4- benzoquinone)methane (Bis-CoQ0), which couples t...

A methylene-bridged bis-coenzyme Q(0), bis(2,3-dimethoxy-5-methyl-l,4-benzoquinone)methane (Bis-CoQ(0)), that shows intramolecular electronic communications has been synthesized for the first time. By employing electrochemical, in situ UV/Vis, and electron paramagnetic resonance (EPR) spectroelectrochemical techniques, the unstable reduced intermed...

6-Vinyl coenzyme Q(0) serves as a convenient starting material for the formation of electropolymerized coenzyme Q(0) on glassy carbon electrodes and the modified electrodes displays electrocatalytic activity toward NADH (β-nicotinamide adenine dinucleotide) oxidation. The detection of NADH was measured by differential pulse voltammetry, which revea...

A novel one-step synthesis route to ordered mesoporous silica-pillared clay (SPC) with cantonic−anionic mixed-gallery templates has been successfully established. This approach involves the type and formation of surfactant mixture for SPC through intragallery ammonia-catalyzed tetraethoxysilane (TEOS). The formation of a precursor with a micromesop...

The metals-doped silica-pillared clay (SPC) materials with ordered pore structure in the gallery were obtained by a surfactant-directed assembly of silica species in the interlayer space of natural montmorillonite (MMT). The novel method afforded SPC derivatives with basal spacings of 4.4–4.5nm, BET specific surface areas of 382.4–472.6m2/g, pore v...

Mesoporous silica-pillared montmorillonite (MMT) materials were synthesized by intragallery ammonia-catalyzed hydrolysis tetraethoxysilane (TEOS). The reaction involved hydrolysis and condensation of tetraethoxysilane in the presence of intragallery surfactants templates. Powder X-ray diffraction (XRD), N(2) adsorption-desorption isotherms, scannin...

The nickel containing silica-pillared clay (Ni-SPC) derivatives were synthesized using a novel method. The characterization results show that Ni-SPC derivatives keep the layered structure and with the uniform mesoporous structure in the gallery regions. The nickel species had been incorporated into the gallery silica frame structure and the higher...

The simultaneous intercalation of surfactants and TEOS into clay interlayers and subsequent intragallery ammonia-catalyzed hydrolysis of TEOS resulted in mesoporous silica-pillared clay (SPC). These SPC materials exhibited refractions corresponding to a basal spacing of 3.7–4.3nm, a uniform pore size of 2.5–3.16nm and large surface areas of 567–576...