Inflammatory bowel diseases (IBDs) like Crohn's disease and ulcerative colitis involve chronic gastrointestinal inflammation. The pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) drives IBD pathogenesis. Anti-TNF-α therapies using monoclonal antibodies (mAbs) like infliximab (INF) help treat IBD but have limitations.
View Article and Find Full Text PDFA "signal on" electrogenerated chemiluminescence (electrochemiluminescence, ECL) aptasensor based on proximity ligation-induced an electrode-bound pseudoknot DNA for sensitive detection of gonyautoxin 1/4 (GTX1/4) was developed on basis of the competitive type reaction mode. Aptamer was adopted as recognition element. Ru(bpy) as ECL signal, was attached on the glassy carbon electrode (GCE) surface modified with nafion and gold nanoparticles (AuNPs) by electrostatic attraction to obtain the ECL platform.
View Article and Find Full Text PDFProximity ligation assay (PLA) is a vigorously developed homogeneous immunoassay assisted by DNA combining dual recognition of target protein by pairs of proximity probes, in which the detection of protein is tactfully converted to the detection of DNA. The booming developments in PLA have enabled a variety of ultrasensitive assays for the detection of protein and this concept of PLA is also extended to the detection of nucleic acids and some small molecule. The association between PLA and electrochemical method, defined as electrochemical proximity ligation assay (ECPLA), has gained much interests in disease diagnosis, food safety and environmental assays with the advantages, such as broad range of targets, simplicity, low cost and rapid response.
View Article and Find Full Text PDFActivation of inflammasomes has been reported in human pancreatic adenocarcinoma (PAAD); however, the expression pattern and functional role of inflammasome-related proteins in PAAD have yet to be identified. In this study, we systemically examined the expression and role of different inflammasome proteins by retrieving human expression data. Several genes were found to be differentially expressed; however, only interferon-inducible protein 16 (IFI16) expression was found to be adversely correlated with the overall survival of PAAD patients.
View Article and Find Full Text PDFIn this work, a simple electrochemiluminescence (ECL) imaging method based on the cell shield of the ECL emission was developed for the morphological and quantitative analysis of living cells under external stimulation. ECL images of MCF-7 cells cultured on or captured at the glassy carbon electrode (GCE) surface in a solution of tris(2,2'-bipyridyl)ruthenium(II)-tri--propylamine were recorded. Important morphological characteristics of living cells, including cell shape, cell area, average cell boundary, and junction distance between two adjacent cells, were directly obtained using the developed negative ECL imaging method.
View Article and Find Full Text PDFMultiple-color emissive carbon dots (C-dots) are gaining increasing attention in various fields. Herein, we report a facile solvothermal method for the synthesis of multiple-color emissive C-dots with the aim of white-light emission. Under single ultraviolet-light excitation, three C-dots emit a easily controlled fluorescent emission wavelength at 440 nm, 500 nm and 610 nm by using different three amines (either ammonium hydroxide, ethylenediamine or p-phenylenediamine, respectively) and pyromellitic dianhydride as molecular precursors while another three C-dots emit a controllable fluorescent emission wavelength at 500 nm, 550 nm and 585 nm by using same three amines and naphthalene-1,4,5,8-tetracarboxylic dianhydride as molecular precursors.
View Article and Find Full Text PDFDevelopment of sensitive method for assay of proteins secreted from small cell population is important for the assessment of cellular heterogeneity. Here, we developed an ultrasensitive electrochemiluminescence (ECL) aptasensor for secreted protein in small cell population of RAW 264.7 cells for cellular heterogeneity assessment.
View Article and Find Full Text PDFThe development of new methods for the detection of redox cycle is important for biological and clinical diagnoses. Here, a new cyclometalated iridium complex, (4-(2-pyridyl) benzaldehyde)Ir (5-chloro-1,10-phenanthroline) ([(4-pba)Ir(5-Cl-phen)]PF, probe ), has been synthesized and applied to rapid, sensitive, and reversible detection and imaging of redox cycle /HO in living cells. The probe is synthesized by using 4-(2-pyridyl) benzaldehyde as main ligand and 5-chloro-1,10-phenanthroline as ancillary ligand.
View Article and Find Full Text PDFA new cyclometalated iridium complex, [(bt)Ir(bpy-Fc)]PF (bt = 2-phenylbenzothiazole, bpy-Fc = 4-ferrocenecarbonyl hydrazinocarbonyl-4'-methyl- 2,2'-bipyridine) (probe 1) was designed and synthesized for rapid photoluminescent (PL) and electrochemiluminescent (ECL) sensing of hypochlorite (ClO). Probe 1 exhibits weak PL and ECL emissions attributed to its electron transfer process. In the presence of ClO, the cleavage of the hydrazine-linked Fc moiety in probe 1 led to the enhancement of both PL and ECL.
View Article and Find Full Text PDFWe report the observation of transient bipolar electrochemical coupling on freely moving 40 nm silver nanoparticles. The use of an asymmetric nanoelectrochemical environment at the nanopore orifice, for example, an acid inside the pipette and halide ions in the bulk, enabled us to observe unusually large current blockages of single Ag nanoparticles. We attribute these current blockages to the formation of H nanobubbles on the surface of Ag nanoparticles due to the coupled faradaic reactions, in which the reduction of protons and water is coupled to the oxidation of Ag and water under potentials higher than 1 V.
View Article and Find Full Text PDFA simple electrochemiluminescence (ECL) immunoassay based on a proximity hybridization-regulated strategy was developed for highly sensitive and specific detection of cell surface protein and protein-overexpressing cancer cells. A biosensor was fabricated by self-assembling a thiolated capture ss-DNA3 (partially hybridize with ss-DNA1 and ss-DNA2) and blocking with 6-mercapto-1-hexanol on a gold electrode surface. Target protein was simultaneously bound by two ss-DNA-tagged antibody probes (DNA1-Ab1 and DNA2-Ab2), while DNA1 and DNA2 were brought in sufficient proximity and hybridized with capture DNA3 on the surface of the biosensor.
View Article and Find Full Text PDFOrganic nanoparticles (NPs) from donor-acceptor based coumarin derivatives, 6-[4-(N,N-diphenylamino)phenyl]-3-ethoxycarbonyl coumarin (DPA-CM), with an average size of 5.82 nm, were synthesized by a facile reprecipitation method using water as a poor solvent and tetrahydrofuran as a good solvent. Red-shifted absorption, blue-shifted photoluminescence emission, and aggregation-induced enhanced electrochemiluminescence (ECL) emission were observed for the DPA-CM NPs in aqueous solution compared with the original DPA-CM in organic solution.
View Article and Find Full Text PDFA proximity hybridization-regulated electrogenerated chemiluminescence (PLA-ECL) bioassay was developed for the detection of α-fetoprotein (AFP) on basis of the sensitization of gold nanoparticles (AuNPs) and target-induced quenching mechanism. Ru(bpy) was used as ECL signal while ferrocene (Fc) was used as ECL quencher. Ru(bpy) was electrostatically adsorbed into the AuNPs/Nafion film prepared by casting the mixture of Nafion and AuNPs onto the surface of glassy carbon electrode (GCE) to form an ECL platform (Ru(bpy)/AuNPs/Nafion/GCE), which displayed strong ECL emissions.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
September 2017
Detection and identification of metal ions by fluorescent turn-on sensors are challenging due to the quenching effect of most of the tested metal ions. In the present work, three ferrocene-modified pyrene-based probes 2-4 were synthesized to act as turn-on fluorescent sensors for Cu. The measurements of fluorescence quantum yield and fluorescence lifetime reveal that ferrocenyl unit can efficiently reduce the fluorescence emission of pyrene moiety.
View Article and Find Full Text PDFA simple and sensitive electrogenerated chemiluminescence biosensor was developed to monitor matrix metalloproteinase 2 (MMP-2) by employing a specific peptide (CGPLGVRGK) as a molecular recognition substrate. Bis(2,2'-bipyridine)-4'-methyl-4-carboxybipyridine-ruthenium N-succinimidyl ester-bis(hexafluorophosphate) (Ru(bpy)2(mcbpy-O-Su-ester)(PF6)2 (Ru1) was used as ECL-emitting species and covalently labeled onto the peptide through NH2-containing lysine on the peptide via acylation reaction to form Ru1-peptide as an ECL probe. An ECL peptide-based biosensor was fabricated by self-assembling the ECL probe onto the surface of gold electrode.
View Article and Find Full Text PDFElectrogenerated chemiluminescence (ECL) with different emission colors is important in the development of multichannel analytical techniques. In this report, five new heteroleptic iridium(III) complexes were synthesized, and their photophysical, electrochemical, and ECL properties were studied. Here, 2-(2,4-difluorophenyl)pyridine (dfppy, complex 1), 2-phenylbenzo[d]thiazole (bt, complex 2), and 2-phenylpyridine (ppy, complex 3) were used as the main ligands to tune the emission color, while avobenzone (avo) was used as the ancillary ligand.
View Article and Find Full Text PDFBackground: Previous observational studies regarding the existence of an association between folate intake and the risk of breast cancer have been inconsistent. This study aimed to summarize the evidence regarding this relationship using a dose-response meta-analytic approach.
Methodology And Principal Findings: We performed electronic searches of the PubMed, EmBase, and Cochrane Library databases to identify studies published through June 2013.
Background: Studies have reported inconsistent results for the existence of an association between polyunsaturated fatty acid (PUFA) intake and risk of lung cancer. The purpose of this study is to summarize the evidence regarding this relationship using a dose response meta-analytic approach.
Methodology And Principal Findings: We searched the PubMed, EmBase, and Cochrane Library electronic databases for related articles published through July 2013.
Background: Studies have reported inconsistent results regarding the existence of an association between folate intake and the risk of lung cancer. The purpose of this study was to summarize the evidence from prospective cohort studies regarding this relationship by using a dose-response meta-analytic approach.
Methodology And Principal Findings: In September 2013, we performed electronic searches in PubMed, Embase, and the Cochrane Library to identify studies examining the effect of folate intake on the incidence of lung cancer.
Background: Omega-3 fatty acids are known to prevent cardiac death. However, previous observational studies have suggested that omega-3 fatty acids are associated with cancer risk in adults. We conducted a meta-analysis based on randomized controlled trials to evaluate the effect of omega-3 fatty acids on the risk of cancer incidence, nonvascular death, and total mortality.
View Article and Find Full Text PDFWe demonstrate an efficient method to design the diffractive phase element for modulating the electric field at the out-of-focus plane of a lens system by using an equivalent Fresnel diffraction in free space. In the monochromatic illumination, we show an example to certify the validity of our method experimentally. In the nonmonochromatic illumination, we theoretically display that the spectral beam splitting and highly confined intensity can be obtained simultaneously at the out-of-focus plane, which has the potential in the solar concentrating system and optical encryption.
View Article and Find Full Text PDFA digital micromirror device (DMD) modulates laser intensity through computer control of the device. We experimentally investigate the performance of the modulation property of a DMD and optimize the modulation procedure through image correction. Furthermore, Laguerre-Gaussian (LG) beams with different topological charges are generated by projecting a series of forklike gratings onto the DMD.
View Article and Find Full Text PDF