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This paper demonstrates the development of a novel nanoparticle-enhanced surface plasmon resonance (SPR) sensing platform for the selective and sensitive in situ detection of nickel(II) ions at concentrations as low as 50 parts per trillion (211 pM). An enhancement in selectivity was achieved by designing a surface sandwich assay involving two different ligands each selective toward nickel(II) ions, namely, N-[5-(3'-maleimidopropylamido)-1-carboxypentyl]iminodiacetic acid (NTA) and polyhistidine. Maleimido-modified NTA was first immobilized on an alkanedithiol-modified gold thin film, followed by the sequential adsorption of Ni(II) ions. Next, polyhistidine-functionalized quasispherical gold nanoparticles, designed to enhance the SPR sensitivity, were specifically adsorbed onto surface Ni(II)-NTA complexes. This process was monitored by real-time SPR. The ability to detect Ni(II) ions as low as 50 parts per trillion (ppt) is a remarkable improvement compared to other optical and colorimetric techniques utilizing nanoparticles and is comparable to what can be achieved by state-of-the-art inductively coupled plasma mass spectrometry (ICP-MS). The improved selectivity for Ni(II) ions by the sandwich assay approach was confirmed by comparing measurements involving other divalent cations such as Zn(II), Pb(II), and Cu(II), some of which individually possess binding affinities toward either the NTA or histidine moieties. [ABSTRACT FROM AUTHOR]

Here we propose a new scheme for bonding poly(dimethylsiloxane) (PDMS), namely, a “chemical gluing”, at room temperature by anchoring chemical functionalities on the surfaces of PDMS. Aminosilane and epoxysilane are anchored separately on the surfaces of two PDMS substrates, the reaction of which are well-known to form a strong amine−epoxy bond, therefore acting as a chemical glue. The bonding is performed for 1 h at room temperature without employing heat. We characterize the surface properties and composition by contact angle measurement, X-ray photoelectron spectroscopy analysis, and fluorescence measurement to confirm the formation of surface functionalities and investigate the adhesion strength by means of pulling, tearing, and leakage tests. As confirmed by the above-mentioned analyses and tests, PDMS surfaces were successfully modified with amine and epoxy functionalities, and a bonding based on the amine−epoxy chemical gluing was successfully realized within 1 h at room temperature. The bonding was sufficiently robust to tolerate intense introduction of liquid whose per minute injection volume was almost 2000 times larger than the total internal volume of the microchannel used. In addition to the bonding of PDMS−PDMS homogeneous assembly, the bonding of the PDMS−poly(ethylene terephthalate) heterogeneous assembly was also examined. We also investigate the potential use of the multifunctionalized walls inside the microchannel, generated as a consequence of the chemical gluing, as a platform for the targeted immobilization. [ABSTRACT FROM AUTHOR]

We report on the targeted imaging of breast cancer using self-assembled levan nanoparticles. Indocyanine green (ICG) was encapsulated in levan nanoparticles via self-assembly. Levan-ICG nanoparticles were found to be successfully accumulated in breast cancer via specific interaction between fructose moieties in levan and overexpressed glucose transporter 5 in breast cancer cells. [ABSTRACT FROM AUTHOR]

In this paper, we report for the first time that graphene oxide (GO) can interact with mutagenic DNA but not intact DNA. After UV-irradiated fluorophore-linked DNA containing thymine repeats was mixed with GO, a decrease in fluorescence was observed in a time-dependent manner. In contrast, no fluorescence change was observed with intact DNA, indicating that UV irradiation of DNA resulted in the formation of mutagenic bases. Because GO is known to act as a fluorescence quencher, the decreased fluorescence implies adsorption of the UV-irradiated DNA onto GO. It appears that the decreased fluorescence might result from the greater accessibility of hydrophobic methyl groups and phenyl rings of thymine dimers to GO and from deformed DNA structures with less effective charge shielding under salt-containing conditions. Using this affinity of GO for mutagenic DNA, we could detect UV-irradiated DNA at concentrations as low as 100 pM. We were also able to analyze the ability of phototoxic drugs to catalyze the formation of mutagens under UV irradiation with GO. Because our method is highly sensitive and feasible and does not require the pretreatment of DNA, we propose that it could accelerate the screening of potential phototoxic drug candidates that would be able to sensitize mutagenic dsDNA. [ABSTRACT FROM AUTHOR]

We report a simple, one-pot process for hydroxyl-functionalized gold nanocrystals with precise morphology control by a surface regulating copolymer. The copolymer, poly(vinyl pyrrolidone-ran-vinyl acetate) (PVP-PVAc), has two distinct moieties including pyrrolidone for nanoparticle formation and acetate for additional functionalization. The particle sizes are readily controlled in the range of 35−80 nm by changing the solvent volume, and the shapes are tuned from octahedral to cuboctahedral and cubic by the addition of AgNO3. Concomitantly, hydrolysis of the acetate groups during the reaction generates multiple hydroxyl groups on the particle surface, which can readily conjugate with versatile functionalities through esterification. This copolymer-based process achieves the synthesis, morphology control, and functionalization of gold nanocrystals via a one-step reaction, as this is superior to the other multistep synthetic procedures. [ABSTRACT FROM AUTHOR]

Effective tracking of immunotherapeutic cells is essential for monitoring the migration of injected cells to the target tissue. Here we report the use of near-infrared (NIR) -emitting fluorescent semiconductor nanocrystals, called quantum dots (QDs), for noninvasive in vivo tracking of dendritic cell (DC) migration into lymph nodes. The effect of QDs on DC viability and maturation was systematically investigated using MTT assays and FACS analysis. We found that the labeling of DCs with QDs had no effect on DC phenotype or maturation potential. Cytokine and migration assays revealed that there were no significant changes in either cytokine production or chemokine-dependent migration of QD-labeled DCs relative to unlabeled cells; in both labeled and unlabeled cells, cytokine production and migratory capacity was increased by stimulation with lipopolysaccharide. Furthermore, QDs did not influence allogenic naive T cell activation or uptake of exogenous antigens. Notably, we also demonstrated that it was possible to track QD-labeled DCs injected into the footpad into popliteal and inguinal lymph nodes using NIR fluorescence. Taken together, our protocols establish the potential of noninvasive in vivo imaging of NIR-emitting QDs for tracking immunotherapeutic cells. [ABSTRACT FROM AUTHOR]

Antibody immobilization on a solid support is an essential process for the development of most immune-based assay systems. The choice of the immobilization method greatly affects antibody–antigen interactions on the assay surface. For the past several years, numerous strategies have been reported to control antibody immobilization, mainly by directing the orientation, stability, and density of bound antibodies on different assay platforms. Here we discuss recent developments in antibody immobilization methods with a particular focus on the strengths and limitations of reported approaches, and thereby provide a useful guideline for the selection of suitable antibody coupling procedures. [ABSTRACT FROM AUTHOR]

Real-time monitoring of cellular dynamics in living organisms is highly challenging. We developed a multi-imaging vector based on 2A peptides. Live imaging of subcellular compartments can be performed following the transfection of cells with another vector, the multi-labeling vector, which contains localization signals and various fluorescent protein variants. [ABSTRACT FROM AUTHOR]

A shape auxiliary approach for the synthesis of shape-controlled gold nanocrystals with functional moieties is established; carboxylate-functionalized gold polyhedra were successfully synthesized in a one-pot reaction in the presence of poly(dimethylaminoethyl methacrylate), which contains the dimethylaminoethyl group as a shape auxiliary. [ABSTRACT FROM AUTHOR]

A shape auxiliary approach for the synthesis of shape-controlled gold nanocrystals with functional moieties is established; carboxylate-functionalized gold polyhedra were successfully synthesized in a one-pot reaction in the presence of poly(dimethylaminoethyl methacrylate), which contains the dimethylaminoethyl group as a shape auxiliary. [ABSTRACT FROM AUTHOR]

The dopamine precursor L-3,4-dihydroxyphenylalanine (L-DOPA) is widely used as a therapeutic choice for the treatment of patients with Parkinson's disease. However, the long-term use of L-DOPA leads to the development of debilitating involuntary movements, called L-DOPA-induced dyskinesia (LID). The cAMP/protein kinase A (PKA) signaling in the striatum is known to play a role in LID. However, from among the nine known adenylyl cyclases (ACs) present in the striatum, the AC that mediates LID remains unknown. To address this issue, we prepared an animal model with unilateral 6-hydroxydopamine lesions in the substantia nigra in wild-type and AC5-knock-out (KO) mice, and examined behavioral responses to short-term or long-term treatment with L-DOPA. Compared with the behavioral responses of wild-type mice, LID was profoundly reduced in AC5-KO mice. The behavioral protection of long-term treatment with L-DOPA in AC5-KO mice was preceded by a decrease in the phosphorylation levels of PKA substrates ERK (extracellular signalregulated kinase) 1/2, MSK1 (mitogen- and stress-activated protein kinase 1), and histone H3, levels of which were all increased in the lesioned striatum of wild-type mice. Consistently, FosB/ΔFosB expression, which was induced by long-term L-DOPA treatment in the lesioned striatum, was also decreased in AC5-KO mice. Moreover, suppression of AC5 in the dorsal striatum with lentivirusshRNA- AC5 was sufficient to attenuate LID, suggesting that the AC5-regulated signaling cascade in the striatum mediates LID. These results identify the AC5/cAMP system in the dorsal striatum as a therapeutic target for the treatment of LID in patients with Parkinson's disease. [ABSTRACT FROM AUTHOR]

One of the main challenges in the development of new analytical platforms for ultrasensitive bioaffinity detection is jointly achieving a wide dynamic range in target analyte concentration, especially for approaches that rely on multistep processes as a part of the signal amplification mechanism. In this paper, a new surface-based sandwich assay is introduced for the direct detection of B-type natriuretic peptide (BNP), an important biomarker for cardiac failure, at concentrations ranging from 1 aM to 500 nM. This was achieved using nanoparticle-enhanced surface plasmon resonance (SPR) where a DNA aptamer is immobilized on a chemically modified gold surface in conjunction with the specific adsorption of antiBNP coated gold nanocubes in the presence of the biomarker target. A concentration detection range greater than eleven orders of magnitude was achieved through dynamic control of only the secondary nanoparticle probe concentration. Furthermore, detection at low attomolar concentrations was also achieved in undiluted human serum. [ABSTRACT FROM AUTHOR]

The ability of dip-pen nanolithography (DPN) to generate nano- or microarrays of soft or hard materials (e.g., small molecules, DNA, proteins, nanoparticles, sols, and polymers) in a direct-write manner has been widely demonstrated. The transporting of large-sized ink materials such as bacteria, however, remains a significant challenge with this technique. The size limitation of the water meniscus formed between the DPN tip and the solid surface becomes a bottleneck in such diffusion-based molecular transport experiments. Herein, we report a straightforward "stamp-on" DPN method that uses a nanostructured poly(2-methyl-2-oxazoline) hydrogel-coated tip and carrier agents to generate patterns of micrometer-sized Escherichia coli JM 109 bacterial cells. We demonstrate that this approach enables the deposition of a single bacterial cell array on a solid surface or arrays of layers of multiple cells by modulating the viscosity of the "ink" solution. Fluorescence microscopy images indicated that the deposited bacterial cells were kept alive on Luria-Bertani-agar layered solid surfaces after DPN patterning. [ABSTRACT FROM AUTHOR]

Calsequestrin (CEQ), the major intrasarcoplasmic reticulum calcium storage protein, undergoes dynamic polymerization and depolymerization in a Ca2+-dependent manner. However, no direct evidence of CEQ depolymerization in vivo with physiological relevance has been obtained. In the present study, live cell imaging analysis facilitated characterization of the in vivo dynamics of the macromolecular CEQ structure. CSQ2 appeared as speckles in the presence of normal sarcoplasmic reticulum (SR) Ca2+ that were decondensed upon Ca2+ depletion. Moreover, CSQ2 decondensation occurred only in the stoichiometric presence of junctin (JNT). When expressed alone, CSQ2 speckles remained unchanged, even after Ca2+ depletion. FRET analysis revealed constant interactions between CSQ2 and JNT, regardless of the SR Ca2+ concentration, implying that JNT is an essential component of the CEQ scaffold. In vitro solubility assay, electron microscopy, and atomic force microscopy studies using purified recombinant proteins confirmed Ca2+ and JNT-dependent disassembly of the CSQ2 polymer. Accordingly, we conclude that reversible polymerization and depolymerization of CEQ are critical in SR Ca2+ homeostasis. [ABSTRACT FROM AUTHOR]

A multiplexed assay technique to measure the photocatalytic activity (PCA) of nanoparticles (NPs) in aqueous suspension was developed based on the observation of TiO2NPs-photocatalytic oxidation rate of NADH by monitoring the fluorescence intensities. 96 sample solutions of a small volume (<150 μL) could be assayed in a single run without separation of NPs within 15 min. PCA values can be measured with high sensitivity and low experimental uncertainties through the observation at various concentrations of photocatalyst, substrate, aqueous protons and pH buffer ions in a short measurement time. [ABSTRACT FROM AUTHOR]

We report on the development of an enzyme-amplified sandwich-type immunosensor based on a thin gold film sputtered on an anodic nanoporous niobium oxide (Au@Nb2O5) electrode. The electrocatalytic activity of enzymatically amplified electroactive species and a stable electrode consisting of Au@Nb2O5 were used to obtain a powerful signal amplification of the electrochemical immunobiosensor. The method using this electrochemical biosensor based on an Au@Nb2O5 electrode provides a much better performance than those based on conventional bulk gold or niobium oxide electrodes. Our novel approach does not require any time-consuming cleaning steps to yield reproducible electrochemical signals. In addition, the strong adhesion of gold films on the niobium oxide electrodes offers a very stable substrate during electrochemical biosensing. Cyclic voltammetry measurements indicate that non-specific binding of proteins to the modified Au@Nb2O5 surface is sufficiently low to be ignored in the case of our novel system. Finally, we demonstrated the ability of the biosensor based on an Au@Nb2O5 offering the enhanced performance with a high resolution and sensitivity. Therefore, it is expected that the biosensor based on an Au@Nb2O5 has great potential for highly efficient biological devices. [ABSTRACT FROM AUTHOR]

We report on the development of an enzyme-amplified sandwich-type immunosensor based on a thin gold film sputtered on an anodic nanoporous niobium oxide (Au@Nb2O5) electrode. The electrocatalytic activity of enzymatically amplified electroactive species and a stable electrode consisting of Au@Nb2O5 were used to obtain a powerful signal amplification of the electrochemical immunobiosensor. The method using this electrochemical biosensor based on an Au@Nb2O5 electrode provides a much better performance than those based on conventional bulk gold or niobium oxide electrodes. Our novel approach does not require any time-consuming cleaning steps to yield reproducible electrochemical signals. In addition, the strong adhesion of gold films on the niobium oxide electrodes offers a very stable substrate during electrochemical biosensing. Cyclic voltammetry measurements indicate that non-specific binding of proteins to the modified Au@Nb2O5 surface is sufficiently low to be ignored in the case of our novel system. Finally, we demonstrated the ability of the biosensor based on an Au@Nb2O5 offering the enhanced performance with a high resolution and sensitivity. Therefore, it is expected that the biosensor based on an Au@Nb2O5 has great potential for highly efficient biological devices. [ABSTRACT FROM AUTHOR]

Here, we describe the fabrication of multispectrally encoded nanoprobes, perfluorocarbon (PFC)/quantum dots (QDs) nanocomposite emulsions, which could provide both multispectral MR and multicolor optical imaging modalities. Our strategy exploited the combination of the multispectral MR properties of four different PFC materials and the multicolor emission properties of three different colored CdSe/ZnS QDs. The PFC/QDs nanocomposite emulsions were fabricated by exchanging hydrophobic ligands coated onto CdSe/ZnS QDs using 1H,1H,2H,2H-perfluorooctanethiol, which renders the QDs to be dispersible in the PFC liquids. To provide biocompatibility, the PFC liquids containing QDs were emulsified into aqueous solutions with the aid of phospholipids. The distinct 19F-based MR images of PFC/QDs nanocomposite emulsions were obtained by selective excitation of the nanocomposite emulsions with magnetic resonance frequency of each PFC, while a specific fluorescence image of them could be selected using appropriate optical filters. The uptake of PFC/QDs nanocomposite emulsions was high in phagocytic cells such as macrophages (90.55%) and dendritic cells (85.34%), while it was low in nonphagocytic I cells (33%). We have also shown that the nanocomposite emulsions were successfully applied to differentially visualize immunotherapeutic cells (macrophages, dendritic cells, and T cells) in vivo. The PFC/QDs nanocomposite emulsions are expected to be a promising multimodality nanoprobe for the multiplexed detection and imaging of therapeutic cells both in vitro and in vivo. [ABSTRACT FROM AUTHOR]

The receptor-type protein tyrosine phosphatases (RPTPs) have been linked to signal transduction, cell adhesion, and neurite extension. PTPRT/RPTPρ is exclusively expressed in the central nervous system and regulates synapse formation by interacting with cell adhesion molecules and Fyn protein tyrosine kinase. Overexpression of PTPRT in cultured neurons increased the number of excitatory and inhibitory synapses by recruiting neuroligins that interact with PTPRT through their ecto-domains. In contrast, knockdown of PTPRT inhibited synapse formation and withered dendrites. Incubation of cultured neurons with recombinant proteins containing the extracellular region of PTPRT reduced the number of synapses by inhibiting the interaction between ecto-domains. Synapse formation by PTPRT was inhibited by phosphorylation of tyrosine 912 within the membrane–proximal catalytic domain of PTPRT by Fyn. This tyrosine phosphorylation reduced phosphatase activity of PTPRT and reinforced homophilic interactions of PTPRT, thereby preventing the heterophilic interaction between PTPRT and neuroligins. These results suggest that brain-specific PTPRT regulates synapse formation through interaction with cell adhesion molecules, and this function and the phosphatase activity are attenuated through tyrosine phosphorylation by the synaptic tyrosine kinase Fyn. [ABSTRACT FROM AUTHOR]

Here we report new photoactivable antibody binding proteins, which site-selectively capture antibodies and form covalent conjugates with captured antibodies upon irradiation. The proteins allow the site-selective tagging and/or immobilization of antibodies with a highly preferred orientation and omit the need for prior antibody modifications. The minimal Fc-binding domain of protein G, a widely used antibody binding protein, was genetically and chemically engineered to contain a site-specific photo cross-linker, benzophenone. In addition, the domain was further mutated to have an enhanced Fc-targeting ability. This small engineered protein was successfully cross-linked only to the Fc region of the antibody without any nonspecific reactivity. SPR analysis indicated that antibodies can be site-selectively biotinylated through the present photoactivable protein. Furthermore, the system enabled light-induced covalent immobilization of antibodies directly on various solid surfaces, such as those of glass slides, gold chips, and small particles. Antibody coupling via photoactivable antibody binding proteins overcomes several limitations of conventional approaches, such as random chemical reactions or reversible protein binding, and offers a versatile tool for the field of immunosensors. [ABSTRACT FROM AUTHOR]

A versatile biolinker for efficient antibody immobilization was prepared by site-specific coupling of protein G to DNA oligonucleotide. This protein G-DNA conjugate ensures the controlled immobilization of an antibody to the in- tended area on the surface of bioassay chips or particles, while maintaining the activity and orientation of the bound antibody. Streptococcus protein G tagged with a cysteine residue at the N-terminus was chemically linked to amine-modified, single-stranded DNA. SPR analysis indicated that the protein G-DNA conjugates sequence-specifically bind to complementary surface-bound DNA probes. More importantly, the resulting protein G, which is hybridized onto the DNA surface, possesses a greater antibody/antigen binding ability than even properly oriented protein G linked on the chip surface by chemical bonding. Antibody targeting on glass slides could also be achieved by using this linker system without modifying or spotting antibodies. Moreover, the protein G-DNA conjugate provided a simple but effective method to label DNA-functionalized gold nanoparticles with target antibodies. The DNA-linked protein G construct introduced in this study offers a useful strategy to manage antibody immobilization in many immunoassay systems. [ABSTRACT FROM AUTHOR]

Protein G is an antibody binding protein, which specifically targets the Fc region of an antibody. It therefore has been widely used to immobilize different types of antibodies in numerous immunoassays. Here, we have engineered Streptococcus protein G to contain various numbers of cysteine residues at the N-terminus and therefore to form well-oriented protein G films on bare gold. SPR and SPR imaging analyses indicated that a gold surface treated with cysteine-tagged protein G possesses a superior antibody binding ability compared to one treated with tag-free protein G. AFM images indicated a higher surface coverage by antibody binding on the cysteine-tagged protein G surface than the intact protein G surface. The proper orientation of cysteine-tagged protein G on a gold surface also afforded better orientation of immobilized antibodies, resulting in enhanced antigen detection. Moreover, the protein G surfaces maintained their high antibody binding ability during multiple rounds of antibody interaction tests. The cysteine-tagged protein G constructed in this study can be a valuable link for oriented antibody immobilization in a variety of immunosensors. [ABSTRACT FROM AUTHOR]

We have constructed a novel platform for the oriented buildup of immunoglobulins on a gold surface for a surface plasmon resonance imaging microarray. To this end, genetically engineered glutathione S-transferase proteins bearing one, two, and three Fc-specific B-domains in protein G from Streptococci (GST-GB1, -GB2, and -GB3, respectively) were produced. In order to tether these GST-GBx proteins specifically, a novel glutathione-derivatized ligand (LA-GSH) was also synthesized from a biaminated tri(ethylene glycol) backbone. Each end of the backbone was further functionalized with a maleimide group for a glutathione modification and a lipoic acid for surface immobilization. The glutathione ligand demonstrated a negligible nonspecific protein adsorption toward other spectator proteins while showing a strong specific association toward GST-GBx proteins. This Fc-specific surface exhibited at least a 2-fold enhancement in the immunoglobulin density (from human and mouse) with its antigen capture capability totally conserved compared to a covalently tethered GBx proteins. A single antibody tethered on the GST-GBx is estimated to capture two antigens (enhanced green fluorescent protein), and this antigen capture ratio seems to be the most efficient value ever observed. [ABSTRACT FROM AUTHOR]

An efficient strategy for immobilizing proteins on a gold surface was developed by employing the gold binding polypeptide (GBP) as a fusion partner. Using the enhanced green fluorescent protein (EGFP), severe acute respiratory syndrome coronavirus (SARS-CoV) envelope protein (SCVme), and core streptavidin (cSA) of Streptomyces avidinii as model proteins, specific immobilization of the GBP-fusion proteins onto the gold nanoparticles and generation of protein nanopatterns on the bare gold surface were demonstrated. The GBP-fused SCVme bound to gold nanoparticles successfully interacted with its antibody and showed changes in absorbance and color, allowing efficient diagnosis of SARS-CoV. The fusion proteins could be successfully immobilized on the gold surface by nanopatterning and microcontact printing as examined by atomic force microscopy and surface plasmon resonance analysis. The poly(dimethylsiloxane) microfluidic channels were created on the gold surface and were used for antigen-antibody and DNA-DNA interaction studies. Specific immobilization of GBP-EGFP fusion protein and its interaction with the antibody in the microchannels could be demonstrated. By immobilizing the DNA probe through the use of GBP-fused cSA, specific hybridization of the target DNA prepared from Salmonella could also be achieved. The GBP-fusion method allows immobilization of proteins onto the gold surface without surface modification and in bioactive forms suitable for studying protein-protein, DNA-DNA, and other biomolecular interaction studies Furthermore, these studies can be carried out in a microfluidic system, which allows high-throughput analysis of biomolecular interactions. [ABSTRACT FROM AUTHOR]

In a recent study, we reported the results of a rapid high-throughput expression analysis of the affinity-tagged proteins present in total cell lysates, using a surface plasmon resonance (SPR) imaging protein chip system. In this paper, we describe a novel method, which is able to sequentially carry out a recombinant Escherichia coli culture, as well as the detection and purification of the expressed proteins on a single microwell chip, fabricated on a two-dimensional thin gold film. Following the induction of the protein on the microwell chip, the E. coli cells were lysed on the chip via the addition of lysozymes, and the expressed glutathione S-transferase-fused green fluorescent protein (GST–GFP) was then purified on the chip via affinity interaction with the glutathionylated gold surface of the chip. Finally, the expressed protein was directly detected using the surface plasmon resonance (SPR) imaging system. This system saves a substantial amount of time, experimental resources, and labor, by allowing for the complicated and labor-intensive procedures inherent to the production of recombinant proteins to be conducted on a single microwell chip, simply and economically. [ABSTRACT FROM AUTHOR]

The article investigates the "doughnut effect" in Cy3-labeled protein microarrays using scanning near-field optical microscope. The study has emphasized on the micron sized spots of human Immunoglobin G protein, with and without a Cy3 dye labeling, which have been fabricated on glass substrates by an immobilization method that has made use of calixcrown derivatives termed Prolinker.

A surface plasmon resonance imaging-based Ni2+-iminodiacetic acid-coated gold chip system was developed to enable specific detection of a hexahistidine-tagged recombinant protein in crude extracts or in column chromatography fractions. This system is especially advantageous for high-throughput analysis of multiple proteins. [ABSTRACT FROM AUTHOR]

For the electrical detection of target DNA (partial avian influenza virus/H1N1/HA sequence) prepared viaasymmetric PCR, we fabricated DNA-templated conducting gold nanowire bridges on planar nanogap electrodes using positively charged gold nanoparticles. [ABSTRACT FROM AUTHOR]

Paramagnetic gold nanostructures were synthesized by combining the paramagnetism of gadolinium with the plasmonic properties of gold nanoparticles and used for dual modal (MRI and optical) imaging and phototherapy of breast cancer cells. [ABSTRACT FROM AUTHOR]

Several nucleophiles such as proteins or poly(ethyleneimine) could be easily conjugated with a 11-(2,4-dinitro-5-fluorobenzene)undecenamide (DFUA) monolayer photochemically prepared on a silicon (100) surface. [ABSTRACT FROM AUTHOR]