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Eva Vargas, Eloy Povedano, Víctor Ruiz-Valdepeñas Montiel, Rebeca M Torrente-Rodríguez, Mohamed Zouari, Juan José Montoya, Noureddine Raouafi, Susana Campuzano, José M Pingarrón
This work reports an amperometric biosensor for the determination of miRNA-21, a relevant oncogene. The methodology involves a competitive DNA-target miRNA hybridization assay performed on the surface of magnetic microbeads (MBs) and amperometric transduction at screen-printed carbon electrodes (SPCEs). The target miRNA competes with a synthetic fluorescein isothiocyanate (FITC)-modified miRNA with an identical sequence for hybridization with a biotinylated and complementary DNA probe (b-Cp) immobilized on the surface of streptavidin-modified MBs (b-Cp-MBs)...
March 15, 2018: Sensors
Shuwei Zhang, Chun Yang, Emmanuel Idehen, Shi Lei, Lishuang Lv, Shengmin Sang
Black tea consumption has been associated with many health benefits including the prevention of cancer and heart disease. However, the chemical composition of black tea has not been fully explored. Most studies have examined different interactions between the four major tea catechins, and few studies have examined the interaction between catechins and other components in tea. In the present study, we tested our hypothesis that the ortho-dihydroxyl structure of chlorogenic acid (CGA) could react with the vic-trihydroxy structure of (-)-epigallocatechin 3-gallate (EGCG) and (-)-epigallocatechin (EGC) to generate theaflavin-type of compounds during black tea fermentation...
March 13, 2018: Journal of Agricultural and Food Chemistry
Puay-Wah Phuan, Guido Veit, Joseph-Anthony Tan, Ariel Roldan, Walter E Finkbeiner, Peter M Haggie, Gergely L Lukacs, Alan S Verkman
The most common cystic fibrosis-causing mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) is deletion of phenylalanine at residue 508 (∆F508). The ∆F508 mutation impairs folding of nucleotide binding domain 1 (NBD1) and interfacial interactions of NBD1 and the membrane spanning domains. Here, we report a domain-targeted screen to identify ∆F508-CFTR modulators that act on NBD1. A biochemical screen for ΔF508-NBD1 cell surface expression was done in Madin-Darby canine kidney cells expressing a chimeric reporter consisting of ΔF508-NBD1, the CD4 transmembrane domain, and an extracellular horseradish peroxidase (HRP) reporter...
March 1, 2018: SLAS Discovery
Haiyan Wang, Huanshun Yin, Hua Huang, Kelin Li, Yunlei Zhou, Geoffrey I N Waterhouse, Hai Lin, Shiyun Ai
Herein, a novel dual-signal amplified photoelectrochemical (PEC) biosensor was successfully developed for the highly selective detection of N6 -methyladenosine (m6 A) methylated RNA. The PEC biosensor comprised BiVO4 -110-TiO2 heterojunction and gold nanoparticle decorated MoS2 (MoS2 -AuNPs) as the photoactive materials, horseradish peroxidase conjugated biotin (HRP-Biotin) as the enzymatic unit, Ag+ -mediated cytosine pairs (C-Ag+ -C) as the signal amplification unit, and the anti-m6 A antibody as the m6 A methylated RNA recognition unit...
February 27, 2018: Biosensors & Bioelectronics
E R Herrero, N Boon, K Bernaerts, V Slomka, T Verspecht, M Quirynen, W Teughels
BACKGROUND AND OBJECTIVE: Little is known about the initiation of dysbiosis in oral biofilms, a topic of prime importance for understanding the etiology of, and preventing, periodontitis. The aim of this study was to evaluate the effect of different concentrations of crevicular and salivary peroxidase and catalase on dysbiosis in multispecies biofilms in vitro. MATERIAL AND METHODS: The spotting technique was used to identify the effect of different concentrations of myeloperoxidase, lactoperoxidase, erythrocyte catalase, and horseradish peroxidase in salivary and crevicular fluid on the inhibitory effect of commensals on pathobiont growth...
March 8, 2018: Journal of Periodontal Research
Rui Shen, Peipei Liu, Yiqiu Zhang, Zhao Yu, Xuyue Chen, Lu Zhou, Baoqing Nie, Anna Żaczek, Jian Chen, Jian Liu
As an important signaling molecule, hydrogen peroxide (H2O2) secreted externally by the cells influences cell migration, immunity generation, and cellular communications. Herein, we have developed a microfluidic approach with droplets in combination with Au nanoclusters for the sensitive detection of H2O2 secreted by a single cell. Isolated in the ultrasmall volume (4.2 nL) of a microdroplet, single-cell secreted H2O2 can initiate dramatic fluorescence changes of horseradish peroxidase-Au nanoclusters. We have demonstrated an ultrahigh sensitivity (200-400 attomole H2O2 directly measured from a single cell) with good specificity...
March 7, 2018: Analytical Chemistry
Jiyue Wen, Weizhuo Lu, Zhenzhen Liu, Jihong Meng
AIMS: To confirm the different characteristics of genotype-specific and common neutralizing epitopes of hepatitis E virus (HEV). METHODS: A competitive binding assay was established with known genotype-common neutralizing monoclonal antibodies (mAbs) 3G1 and 5G5 as well as genotype-specific neutralizing mAbs 2B1 and 4C5. HEV ORF2 recombinant p166W01 derived from genotype 1 and p166Chn derived from genotype 4 were used as coated antigens, to determine whether the mAbs recognize independent, similar, or overlapping epitopes...
March 6, 2018: Intervirology
Ying Wang, Meiling Wang, Lu Han, Yanjun Zhao, Aiping Fan
In the present study, the effects of nine compounds on the luminol-O2 chemiluminescence (CL) reaction catalyzed by gold nanoparticles (Au NPs) were investigated. p-Iodophenol (PIP), known as a traditional enhancer in horseradish peroxidase (HRP)-catalyzed luminol-H2 O2 CL reaction, exhibited the highest enhancement effect on the luminol-O2 -Au NPs CL reaction. The addition of PIP at a final concentration of 1.25 mM to luminol-O2 -Au NPs CL system enhanced the CL signal almost 30-fold. Interestingly, the enhanced CL reaction exhibited a slow and intense CL signal which is different from the CL profile of luminol-H2 O2 -Au NPs CL system reported in previously...
May 15, 2018: Talanta
Xiaoyu Li, Junjing Li, Caixia Zhu, Xiaohua Zhang, Jinhua Chen
In this work, a new electrochemical immunosensor was developed for prion protein assay based on hybridization chain reaction (HCR) with hemin/G-quadruplex DNAzyme for signal amplification. In this amplification system, the hemin/G-quadruplex DNAzyme simultaneously mimicked the biocatalytic functions for H2 O2 reduction and L-cysteine oxidation. In the presence of L-cysteine, the hemin/G-quadruplex catalyzed the oxidation of L-cysteine to L-cystine. At the same time, H2 O2 was produced under the oxygen condition...
May 15, 2018: Talanta
Jingjing Guo, Yan Wang, Min Zhao
Ferrous(II) phosphate nanoflowers (Fe3 (PO4 )2 ·8H2 O NFs) were synthesized by a facial co-precipitation method. The structure, composition and morphology were characterized by XRD, EDX, element mapping and FESEM. The as-prepared Fe3 (PO4 )2 ·8H2 O NFs exhibited excellent intrinsic peroxidase-like activity. Steady-state kinetic studies showed that Fe3 (PO4 )2 ·8H2 O NFs exhibited stronger affinities with 3,3,5,5-tetramethylbenzidine (TMB) and H2 O2 as the substrates compared with the natural horseradish peroxidase (HRP) and the catalytic constant (kcat ) value was even higher than HRP and other reported nanomaterial based peroxidase mimics...
May 15, 2018: Talanta
Babak Rezaei, Ahmad Mousavi Shoushtari, Mohammad Rabiee, Lokman Uzun, Wing Cheung Mak, Anthony P F Turner
A sandwich-type nanostructured immunosensor based on carboxylated multi-walled carbon nanotube (CMWCNT)-embedded whiskered nanofibres (WNFs) was developed for detection of cardiac Troponin I (cTnI). WNFs were directly fabricated on glassy carbon electrodes (GCE) by removing the sacrificial component (polyethylene glycol, PEG) after electrospinning of polystyrene/CMWCNT/PEG nanocomposite nanofibres, and utilised as a transducer layer for enzyme-labeled amperometric immunoassay of cTnI. The whiskered segments of CMWCNTs were activated and utilised to immobilise anti-cTnT antibodies...
May 15, 2018: Talanta
Nik Nurhanan Nik Mansor, Tan Toh Leong, Eka Safitri, Dedi Futra, Nurul Saadah Ahmad, Dian Nasriana Nasuruddin, Azlin Itnin, Ida Zarina Zaini, Khaizurin Tajul Arifin, Lee Yook Heng, Nurul Izzaty Hassan
A tri-enzyme system consisting of choline kinase/choline oxidase/horseradish peroxidase was used in the rapid and specific determination of the biomarker for bacterial sepsis infection, secretory phospholipase Group 2-IIA (sPLA2-IIA). These enzymes were individually immobilized onto the acrylic microspheres via succinimide groups for the preparation of an electrochemical biosensor. The reaction of sPLA2-IIA with its substrate initiated a cascading enzymatic reaction in the tri-enzyme system that led to the final production of hydrogen peroxide, which presence was indicated by the redox characteristics of potassium ferricyanide, K₃Fe(CN)₆...
February 26, 2018: Sensors
Md Wasimul Haque, Shakti Prasad Pattanayak
Background: Breast cancer (BC), because of its invasive characteristics, is one of the most common and deadliest cancers among the female population around the world. Research has demonstrated that AhR signaling also plays a vital role in BC initiation and development as well. Therefore, blocking this pathway to natural interferences paves a new channel for the prevention of BC. Several natural compounds such as flavonoids possess the anticancer activities against different cancers. Objective: The present study has been designed to estimate the chemotherapeutic potential of taxifolin (TAX) against 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma in Sprague-Dawley rats...
January 2018: Pharmacognosy Magazine
Nozlena Abdul Samad, Ahmad Bustamam Abdul, Heshu Sulaiman Rahman, Abdullah Rasedee, Tengku Azmi Tengku Ibrahim, Yeap Swee Keon
Context: Due to increase in the number of patients with impaired immunity, the incidence of liver cancer has increased considerably. Aims: The aim of this study is the investigation the in vitro anticancer effect of zerumbone (ZER) on hepatocellular carcinoma (HCC). Materials and Methods: The anticancer mechanism of ZER was determined by the rat aortic ring, human umbilical vein endothelial cells (HUVECs) proliferation, chorioallantoic membrane, cell migration, and proliferation inhibition assays...
January 2018: Pharmacognosy Magazine
Miyuki Morita, Michiko Tani, Mayuko Onikoshi, Kiyomi Mase, Fumi Masuko
The effects of four detergent enzymes on the Orange II decoloration reaction by horseradish peroxidase (HRP) were investigated. Stainzyme, Lipex, Celluclean, and Savinase did not affect the decoloration reaction up to a concentration of 0.1% Under weak alkaline to alkaline conditions, the presence of four enzymes did not affect the decoloration reaction, but affected the decoloration reaction under neutral to acidic conditions. The effect of Ca2+ and Mg2+ concentrations on Orange II decoloration reactions in the presence of four enzymes was also investigated...
2018: Journal of Oleo Science
Xin-Yuan Qiu, Lv-Yun Zhu, Chu-Shu Zhu, Jia-Xin Ma, Tao Hou, Xiao-Min Wu, Si-Si Xie, Lu Min, De-An Tan, Dongyi Zhang, Lingyun Zhu
MicroRNAs have been reported related to multiple diseases and has potential applications in diagnosis and therapeutics. However, detection of miRNAs remains improvable, given their complexity, high cost and low sensitivity of currently. In this study, we attempt to build a novel platform that detects miRNAs at low cost and high efficacy. This detection system contains isothermal amplification, detecting and reporting process based on Rolling Circle Amplification, CRISPR-Cas9, and split-Horseradish Peroxidase techniques...
February 27, 2018: ACS Synthetic Biology
Xingyu Jiang, Yunlei Xianyu, Jing Wu, Yiping Chen, Wenshu Zheng, Mengxia Xie
Multiplexed analysis of molecules with different concentrations requires assays with a tunable detection range. Herein, we outline a strategy that uses click chemistry to controllably assemble horseradish peroxidase to generate enzyme assemblies as probes for multiplexed bioassays. This controllable assembly of enzymes on detection antibodies allows for lab-on-a-chip immunoassays with a tunable detection range from pg/mL to µg/mL. Simultaneous, multiplexed bioassays of clinically relevant inflammatory biomarkers in serum are demonstrated in one lab-on-a-chip format, with a limit of detection of 0...
February 26, 2018: Angewandte Chemie
Lihua Yang, Yang Shi, Jinjin Li, Ling Fang, Tiangang Luan
The potential of horseradish peroxidase (HRP) to catalyze the removal of sulfonamides from water and the effects of different H2 O2 and HRP concentrations were investigated. Six sulfonamides, each with a five- or six-membered heterocyclic group, including sulfamethoxazole (SMX), sulfathiazole (STZ), sulfapyridine (SPD), sulfadiazine (SDZ), sulfamerazine (SMR) and sulfamethoxypyridazine (SMP) were selected as target compounds. All sulfonamides exhibit a pseudo-first-order dependence of the concentration versus the reaction time...
February 20, 2018: Chemosphere
Gaëlle Coussot, Clément Faye, Aurélie Le Postollec, Michel Dobrijevic
The anti-horseradish peroxidase (HRP) antibody is conventionally used in immunohistochemistry. More recently, it has been used as the key element in a gold standard method to evaluate the functionality of antibody-based materials. However, few information are available about its melting temperature and its stability after exposition to laboratory stress conditions including freeze-drying and freeze-thawing cycles. The aim of this study was to evaluate the effects of these environmental constraints on the anti-HRP antibody in order to further use it as a reference in quality control and in the development of new antibody-based materials...
February 22, 2018: Analytical Biochemistry
Kun Deng, Yong Zhang, Xue-Dong Tong
Methods based on potentiometric measurement have been developed for immunoassays, but most exhibit low sensitivities and are unsuitable for early diagnosis of disease. Herein we design a new potentiometric immunosensing platform for the sensitive detection of carcinoma antigen 15-3 (CA 15-3) by coupling with enzymatic biocatalytic precipitation and a nanogold labeling technique. The sandwich-type immunoreaction is carried out on a monoclonal anti-CA 15-3 capture antibody-modified working electrode, using horseradish peroxidase (HRP) and polyclonal anti-CA 15-3 detection antibody-labeled gold nanoparticles...
February 22, 2018: Analyst
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