A novel single nucleotide polymorphisms detection sensors based on magnetic nanoparticles array and dual-color single base extension.

To fulfill the increasing need for large-scale genetic research, a high-throughput and automated SNPs genotyping method based on gold coated magnetic nanoparticles (GMNPs) array and dual-color single base extension has been designed. Biotinylated single base extension primer were captured onto the GMNPs coated with streptavidin. Dual-color fluorescence single base extension was employed as a tool for SNPs identification, and then a "bead array" was fabricated by spotting GMNPs with fluorophore on the glass slide.

Covalent binding of streptavidin on gold magnetic nanoparticles for bead array fabrication.

In this study, we report the chemical synthesis and functionalization of streptavidin coated gold magnetic nanoparticles (GMNPs) and the immobilization of single-stranded biotinylated oligonucleotides onto these particles. By using covalent interaction or physical adsorption, two kinds of streptavidin coated GMNPs (SA-GMNPs) were prepared. The quantity and stability of streptavidin bound to the GMNPs using different methods were determined by UV-Vis spectrometer.

Preparation of silicotungstenic acid-containing mesoporous materials.

Silicotungstenic acid (STA)-containing mesoporous materials were directly synthesized in a nonaqueous medium by sol-gel method. X-ray powder diffraction showed that both as-synthesized and calcined materials possess mesoporous structure. STA contents in extraction solutions were analyzed with inductively coupled plasma.

Application of smart nanostructures in medicine.

Smart nanostructures are sensitive to various environmental or biological parameters. They offer great potential for numerous biomedical applications such as monitoring, diagnoses, repair and treatment of human biological systems. The present work introduces smart nanostructures for biomedical applications.

An integrated and sensitive detection platform for biosensing application based on Fe@Au magnetic nanoparticles as bead array carries.

A sensitive and selective biosensor platform suited for SNP type using Fe@Au magnetic nanoparticles (GMNPs) to fabricate bead array is described. This new platform integrates the rapid binding kinetics of magnetic nanoparticles carriers, the multiplexing and encoding capabilities of chips, and tagged array. As a DNA sensor, the biotinylated single-stranded DNA was obtained by asymmetry PCR amplification, and then captured by GMNPs modified with streptavidin to form GMNP-ssDNA complexes without further purification.

Preparation, characterization and applications of low-molecular-weight alginate-oligochitosan nanocapsules.

The development of drug-delivering nanoparticles from natural materials for various biomedical applications is an area of great promise. However, the contradictory data on their uncontrollable diameter, unstable structure and toxic effects, highlight the need to study their preparation, characterization and cytotoxic effects in cells. In this work, nanocapsules are made from a type of W/O microemulsion system with low-molecular-weight alginate (LMWALG) and oligochitosan (OCS).

A novel automated assay with dual-color hybridization for single-nucleotide polymorphisms genotyping on gold magnetic nanoparticle array.

A high-throughput and cost-effective single-nucleotide polymorphism (SNP) genotyping method based on a gold magnetic nanoparticle (GMNP) array with dual-color hybridization has been designed. Biotinylated single-strand polymerase chain reaction (PCR) products containing the SNP locus were captured by the GMNPs that were coated with streptavidin. The GMNP array was fabricated by immobilizing single-stranded DNA (ssDNA)-GMNP complexes onto a glass slide using a magnetic field, and SNPs were identified with dual-color fluorescence hybridization.

Chemiluminescent detect of E. coli O157:H7 using immunological method based on magnetic nanoparticles.

The system of chemiluminescent magnetic enzyme-linked immunoassay was developed. E. coli O157:H7 was sandwiched between rabbits anti-E.

Determination of paracetamol with porous electrochemical sensor.

A novel and sensitive electrochemical sensor based on porous pseudo-carbon paste electrode (PPCPE) for paracetamol detection is described. It was demonstrated that PPCPE exhibits a high selectivity and sensitivity toward paracetamol in comparison with polypyrrole modified carbon paste electrode (PCPE), carbon nanotube modified carbon paste electrode (CNTPE) and carbon paste electrode (CPE), and a detection limit as low as 0.005 mM was obtained.

Preparation of SiO2/(PMMA/Fe3O4) from monolayer linolenic acid modified Fe3O4 nanoparticles via miniemulsion polymerization.

SiO2/(PMMA/Fe3O4) composite particles were prepared from linolenic acid (LA) instead of oleic acid (OA) modified Fe3O4 nanoparticles by miniemulsion polymerization. LA has three unsaturated double bonds with which it can polymerizate more easily than OA. And coating Fe3O4 with polymethyl methacrylate (PMMA) polymer beforehand can prevent magnetic nanoparticles from the aggregation that usually comes from the increasing of ionic strength during the hydrolyzation of tetraethoxysilane (TEOS) by the steric hindrance.

Chitosan/sodium tripolyphosphate nanoparticles: preparation, characterization and application as drug carrier.

With the existence of amino groups, chitosan (CS) possesses positive charge, so it can self-assemble with tripolyphotspate (TPP) possessing negative charge via ionic gelation. We here synthesized CS/TPP nanoparticles, and then characterized it with the infrared spectra (IR) and scanning electron microscope (SEM) and transmission electron microscopy (TEM) and used bovine serum albumin (BSA) as a model drug to investigate sustained-release properties of CS/TPP nanoparticles. Infrared spectrum of CS/TPP nanoparticles indicated that CS was cross-linked with TPP.

Improvement on synthesis of different alkyl-phenylboronic acid.

Various alkyl-phenylboronic acids have been widely used in the fields of electronics, chemistry, medicine and biology, especially in glucose sensors and intermediates of medicines. In this paper, the syntheses of two or three different alkyl-phenylboronic acids and the improvement on synthesis processes were studied with Grignard reagent method in detail. The influencing factors such as temperature, reaction time, reactant molar ratio were analyzed with the orthogonal experiment; optimized processes for the preparation of different alkyl-phenylboronic acids were thus obtained using different alkylborates as original materials.

An automated MagStation for high-throughput single nucleotide polymorphism genotyping and the dual-color hybridization.

We designed a novel automated MagStation for high-throughput single nucleotide polymorphism (SNP) discrimination using dual-color hybridization. Magnetic particles (MPs) were used as target DNA carriers. The principle for SNP discrimination in this study was allele specific hybridization using dual-color fluorescent (Cy3, Cy5) probes.

Preparation of SiO2/polymethyl methacrylate/Fe3O4 nanoparticles and its application in detecting E. coli O157:H7 using chemiluminescent immunological method.

This paper described that Fe3O4 nanoparticles were encapsulated with methyl methacrylate (MMA) using linolenic acid (LA) as a crosslinking agent, after which the resulting polymethyl methacrylate (PMMA) embed Fe3O4 nanoparticles (PMMA/Fe3O4) were coated with silica, forming SiO2/ (PMMA/Fe3O4) core-shell structure particles. Then these magnetic nanoparticles (MNPs) were applied in the developed system of chemiluminescent magnetic enzyme-linked immunoassay. E.

Effect of single central base pair mismatch on the conformation and stability of surface immobilized DNA: molecular dynamics studies.

We combine molecular dynamics simulations and relative free energy calculation to investigate how single central base mismatch influence the conformation and stability of surface immobilized DNA. For comparison purpose, molecular dynamics simulations have been performed on a central mismatched duplex and the corresponding perfectly matched duplex, respectively. Simulations have been conducted with the generalized Born model.

High-throughput SNP detection based on PCR amplification on magnetic nanoparticles using dual-color hybridization.

A microarray-based method for detecting single nucleotide polymorphisms (SNPs) using solid-phase polymerase chain reaction (PCR) on magnetic nanoparticles (MNPs) was developed. In this method one primer with a biotin label is captured by streptavidin-coated MNPs (SA-MNPs), and the PCR products are directly amplified on the surface of SA-MNPs in a 96-well plate. The samples are further probed by hybridization with a pair of dual-color probes to determine SNP.

Anodic stripping voltammetry for detection of DNA hybridization with porous pseudo-carbon paste electrode by gold nanoparticle-catalyzed silver enhancement.

A novel and sensitive electrochemical DNA biosensor based on porous pseudo-carbon paste electrode (PPCPE) for DNA immobilization and enhanced hybridization detection is described. PPCPE was fabricated by mixing polymethyl methacrylate (PMMA) microspheres as the template, graphite powders as the filler, pyrrole as the precursor of polymer which actually acted as the paste. After the polymerization of pyrrole catalyzed by Fe3+, the template PMMA microspheres were removed to form PPCPE.

Self-assembly monolayer of 3-aminopropylmethyldiethoxysilane on glassy carbon electrode for albumin detection.

An electrochemical biosensor is fabricated for detecting albumin by self-assembling monolayer of 3-aminopropylmethyldiethoxysilane (APMDES) on the surface of glassy carbon electrode. The compact self-assembled monolayer is obtained when the self-assembling temperature is 303 K, the self-assembling time is 4 h and the concentration of APMDES is 3%. To detect albumin by means of the nanogold-promoted precipitation of silver with the optimal signal-to-noise ratio, the parameters to influence the detection current signals and the background current signals are investigated using anodic stripping voltammetry.

Probing DNA hybridization efficiency and single base mismatch by X-ray photoelectron spectroscopy.

We demonstrated the use of X-ray photoelectron spectroscopy (XPS) to study DNA hybridization. Target DNA labeled with hexachloro-fluorescein (HEX) was hybridized to DNA arrays with four different probes. Each probe dot of the hybridized arrays was detected with XPS.

A detailed investigation for determination of tannic acid by anodic stripping voltammetry using porous electrochemical sensor.

The electrochemical responses of tannic acid have been obtained at porous pseudo-carbon paste electrode (PPCPE), polypyrrole modified carbon paste electrode (PCPE), SBA-15 modified CPE (SBA-MCPE) and carbon paste electrode (CPE) under same conditions, respectively. The results show that the sensitivity of PPCPE is the highest among all the checked electrodes. The detection limit at PPCPE is 0.

Multiplex single nucleotide polymorphisms genotyping using solid-phase single base extension on magnetic nanoparticles.

To fulfill the increasing need for large-scale genetic research, we have developed a new solid-phase single base extension (SBE) protocol on magnetic nanoparticles (MNPs) for multiplex SNP detection using adapter polymerase chain reaction (PCR) products as templates. Extension primers were covalently immobilized on the MNPs, and allele-specific extension took place along the stretch of target DNA for one-color ddNTP incorporation. The MNPs with fluorophores were spotted on a glass slide to fabricate a "bead array" to discriminate their genotypes.

MCM-41 mesoporous material modified carbon paste electrode for the determination of cardiac troponin I by anodic stripping voltammetry.

An anodic stripping voltammetric method for the determination of cardiac troponin I (cTnI) at a MCM-41 mesoporous material modified carbon paste electrode (MCM-MCPE) was investigated. The test was based on the dual monoclonal antibody "sandwich" principle using colloidal gold as a labeled substrate. Four main steps were carried out to obtain the analytical signal, i.

Neurotoxicological effects of 3-nitropropionic acid on the neonatal rat.

An increasing amount of data provides support for the hypothesis that periventricular leukomalacia (PVL) results from pre- or perinatal hypoxia occurring and is a major cause of cerebral palsy. In this work, anoxic and hypoxic-ischemic brain injuries were observed by us, after injection of neurotoxin 3-nitropropionic acid (3-NP) in a neonatal rat model on postnatal day 5 (P5). 3-NP-induced brain injury was examined in fixed brain sections at 24h (P6), 48h (P7), 72h (P8), and 9 days (P14) after 3-NP injection, respectively.

Synthesis and characterization of SiO2/(PMMA/Fe3O4) magnetic nanocomposites.

Magnetic silica nanocomposites (magnetic nanoparticles core coated by silica shell) have the wide promising applications in the biomedical field and usually been prepared based on the famous Stöber process. However, the flocculation of Fe3O4 nanoparticles easily occurs during the silica coating, which limits the amount of magnetic silica particles produced in the Stöber process. In this paper, PMMA/Fe3O4 nanoparticles were used in the Stöber process instead of the "nude" Fe3O4 nanoparticles.