Enzyme-based electrochemical biosensors hold great promise for applications in health/disease monitoring, drug discovery, and environmental monitoring. However, inherently non-conductive nature of proteinaceous enzymes often hampers effective electron transfer at enzyme-electrode interface, limiting biosensor performance of enzyme bioelectrodes. To address this problem, we present an approach to synthesize polyaniline (PAN)-based conductive single enzyme nanocomposites of glucose oxidase (GOx) (denoted as PAN-GOx).
View Article and Find Full Text PDFCoronary artery bypass graft surgery (CABG) is a proven treatment for coronary artery disease. History of a ST-elevation myocardial infarction (STEMI) is considered an independent risk factor for CABG irrespective of timing for an emergency or elective surgery. Patients with STEMI are candidates for both On-pump and Off-pump CABG procedures.
View Article and Find Full Text PDFRecent efforts to identify disadvantaged communities (DACs) on a census tract level have evoked possibilities of attaining transportation justice and vision zero goals in these areas. To identify DACs, the United States Department of Transportation (USDOT) has developed six comprehensive indicators: economy, environment, equity, health, resilience, and transportation access. The indicators are used to explore the associations between DACs (in 71,728 census tracts) and five years of fatal crashes, providing a comprehensive understanding of safety risks.
View Article and Find Full Text PDFThe electrochemical applications of enzymes are often hampered by poor enzyme stability and low electron conductivity. In this work, a novel enzyme nanogel based on atom transfer radical polymerization (ATRP) has been developed for highly sensitive detection of glucose based on ferrocene (Fc) embedded in crosslinked polymer network nanogel. Enzyme surfaces are successively modified with Br initiator, and then in situ atom transfer radical polymerization (ATRP) was performed to build up crosslinked polyacrylamide network.
View Article and Find Full Text PDFCoronary catheterization is usually performed using the transfemoral approach but trans-radial has been increasingly used as an alternative to transfemoral approach due to less vascular complications, earlier ambulation time and improved patient comfort. The aim of the study was to compare the safety and feasibility of trans-radial and transfemoral PCI in the elderly ACS patients. This prospective observational study was conducted in the NICVD, Dhaka from October 2017 to September 2018.
View Article and Find Full Text PDFThe high and selective catalytic activities of tyrosinase (Tyr) have frequently led to its application in sensitive biosensors. However, in affinity-based biosensors, the use of Tyr as a catalytic label is less common compared to horseradish peroxidase and alkaline phosphatase owing to the fact that phenolic Tyr substrates have yet to be investigated in detail. Herein, four phenolic compounds that have lower formal potentials than phenol were examined for their applicability as Tyr substrates, and three reducing agents were examined as potential strong reducing agents for electrochemical-chemical (EC) redox cycling involving an electrode, a Tyr product, and a reducing agent.
View Article and Find Full Text PDFCadmium (Cd) toxicity is a form of soil contamination that causes losses in plant growth and yield. Understanding the effects of Cd-induced changes in physiological and cellular processes will help scientists develop better scientific strategies for sugar beet plant improvement. Cd toxicity triggered a substantial decrease in morphological parameters and total soluble protein in sugar beets, as well as membrane damage and cell death.
View Article and Find Full Text PDFIn horseradish peroxidase (HRP)-based electrochemical immunosensing, an appropriate HRP substrate needs to be chosen to obtain a high electrochemical signal-to-background ratio. This is limited by the unwanted electrochemical reduction of HO, oxidation of the substrate, and the slow electrochemical reduction of the product. Herein, we report acetaminophen (AMP) as a new HRP substrate that allows for highly sensitive immunosensing.
View Article and Find Full Text PDFCoronary heart disease (CHD) is the most common cause of heart disease and serious cause of early death in developed countries around the world. Stress hyper-glycaemia has a bad prognostic implication in hospital outcomes in acute ST elevated myocardial infarction patients. It serves as a marker of myocardial damage, provides information about complications of acute MI and bad prognosis.
View Article and Find Full Text PDFWe propose an electrochemical sensor based on the enhanced electrocatalytic oxidation exhibited on a functionalized poly(tannic acid) coating to detect hydrazine. Tannic acid, a naturally abundant and low-cost polyphenol, was enzymatically polymerized with horseradish peroxidase and subsequently adsorbed on a disposable screen-printed carbon electrode with a short incubation time (30 min). The fabrication method proved to be reproducible (4.
View Article and Find Full Text PDFWe report HRP-catalyzed polymerization of Tannic acid (TA) and application of the poly (Tannic acid) (p(TA)) as a versatile platform for covalent immobilization of biomolecules on various electrode surfaces based on electrochemical oxidation of the p(TA) and subsequent oxidative coupling reactions with the biomolecules. We also used this method for capturing cancer cells through a linker molecule, folic acid (FA). Furthermore, we have demonstrated that enhanced electrocatalytic activity of the p(TA)-modified surface could be used for simultaneous electrochemical determination of biologically important electroactive molecules such as ascorbic acid (AA), dopamine (DA), and uric acid (UA).
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
February 2019
Simple and sensitive competitive immunosensors for small molecules are difficult to obtain, especially in serum containing numerous interfering species (ISs) with different concentrations. Herein, we report a washing-free and sensitive (competitive) displacement immunosensor for cortisol in human serum, based on electron mediation of Os(bpy)Cl between an electrode and a redox label [oxygen-insensitive diaphorase (DI)] (i.e.
View Article and Find Full Text PDFBiosensors for ultrasensitive point-of-care testing require dried reagents with long-term stability and a high signal-to-background ratio. Although ortho-substituted diaromatic dihydroxy and aminohydroxy compounds undergo fast redox reactions, they are not used as electrochemical signaling species because they are readily oxidized and polymerized by dissolved oxygen. In this report, stable, solid 1-amino-2-naphthyl phosphate (1A2N-P) and ammonia-borane (HN-BH) are respectively employed as a substrate for alkaline phosphatase (ALP) and a reductant for electrochemical-chemical (EC) redox cycling.
View Article and Find Full Text PDFEthanolamine plasmalogen (PlsEtn), a major phospholipid in neuronal membranes [60-90 mol% of ethanolamine glycerophospholipid (EtnGpl)], is specifically decreased in brains from patients with Alzheimer's disease (AD). The present study investigated how PlsEtn administration affects cognitive deficits and lipid composition in an animal model of AD. AD model rats were infused with amyloid-β (Aβ) into the cerebral ventricle and divided into three groups.
View Article and Find Full Text PDFWe found that the formylbenzenediazonium (FBD)-grafted organic layers can be degraded by treating with an aqueous solution of salt and Tween. An electrochemical immunoassay was carried out on the degraded surface, which allowed highly sensitive detection of antigen mouse IgG.
View Article and Find Full Text PDFWe present an electrochemically reduced graphene oxide (ERGO)-based electrochemical immunosensing platform for the ultrasensitive detection of an antigen by the sandwich enzyme-linked immunosorbent assay (ELISA) protocol. Graphene oxide (GO) sheets were initially deposited on the amine-terminated benzenediazonium-modified indiun tin oxide (ITO) surfaces through both electrostatic and π-π interactions between the modified surfaces and GO. This deposition was followed by the electrochemical reduction of graphene oxide (GO) for preparing ERGO-modified ITO surfaces.
View Article and Find Full Text PDFDeposition of amyloid β peptide (Aβ) into the brain causes cognitive impairment. We investigated whether prescription pre-administration of n-3 fatty acids improves cognitive learning ability in young rats and whether it protects against learning ability impairments in an animal model of Alzheimer's disease that was prepared by infusion of Aβ(1-40) into the cerebral ventricles of rats. Pre-administration of TAK-085 (highly purified and concentrated n-3 fatty acids containing eicosapentaenoic acid ethyl ester and docosahexaenoic acid ethyl ester) at 300 mg kg(-1) day(-1) for 12 weeks significantly reduced the number of reference memory errors in an 8-arm radial maze, suggesting that long-term administration of TAK-085 improves cognitive leaning ability in rats.
View Article and Find Full Text PDFWe describe an electrochemical oxidative desorption of benzenediazonium-grafted organic layers and immobilized proteins on the layers from indium-tin-oxide electrode surfaces.
View Article and Find Full Text PDFWe report in situ generation of aldehyde-functionalized benzenediazonium cation (ABD) and its use as a suitable linker molecule for fast and selective immobilization of biomolecules on indium-tin-oxide (ITO) electrode surfaces. We prepared ABD through a new reaction procedure, a simultaneous diazotation of the amine group and deprotection of the aldehyde group from an aniline derivative, 2-(4-aminophenyl)-1,3-dithiane, which was revealed on the ITO electrode surfaces through the electrodeposition of the reaction product and the characterization of the resulting surfaces with cyclic voltammetry, X-ray photoelectron spectroscopy, and protein immobilization. We also showed that successive electrodeposition of ABD and probe molecules on individually addressable microarray electrode surfaces can provide a useful platform for efficient detection of multianalyte.
View Article and Find Full Text PDFWe report the use of 1,3-dithiane combined with aryldiazonium cation for the immobilization of biomolecules based on electrochemical addressing.
View Article and Find Full Text PDFAmyloid beta peptide (Abeta)-induced oxidative stress is involved in the pathogenesis of Alzheimer's disease (AD). In contrast, green tea catechins confer potent antioxidative defense to brain neurons. Therefore, we examined whether long-term administration of green tea catechins [Polyphenon E (PE): 63% of epigallocatechin-3-gallate, 11% of epicatechin, 6% of (-)-epigallocatechin and 6% of (-)-epicatechin-gallate] prevents cognitive impairment in an animal model of AD, rats infused with Abeta1-40 into the cerebral ventricle.
View Article and Find Full Text PDFAlzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive and memory deterioration. Production and accumulation of beta-amyloid peptide (Abeta) is central to the pathogenesis of AD. Recent studies have demonstrated that PKA/CREB-dependent signaling pathway and long-term potentiation are inhibited by sublethal concentrations of Abeta(1-42) in cultured hippocampus neurons.
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