scholarly journals Application of Conducting Polymer Nanostructures to Electrochemical Biosensors

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 307 ◽  
Author(s):  
Waleed A. El-Said ◽  
Muhammad Abdelshakour ◽  
Jin-Ha Choi ◽  
Jeong-Woo Choi
Keyword(s):  
Conducting Polymers ◽  
Conducting Polymer ◽  
Biological Molecules ◽  
Electrochemical Biosensors ◽  
Biological Targets ◽  
Topographical Effects ◽  
Metal Metal ◽  
Metal Oxide Nanostructures ◽  
The Stability ◽  
Application Fields

Over the past few decades, nanostructured conducting polymers have received great attention in several application fields, including biosensors, microelectronics, polymer batteries, actuators, energy conversion, and biological applications due to their excellent conductivity, stability, and ease of preparation. In the bioengineering application field, the conducting polymers were reported as excellent matrixes for the functionalization of various biological molecules and thus enhanced their performances as biosensors. In addition, combinations of metals or metal oxides nanostructures with conducting polymers result in enhancing the stability and sensitivity as the biosensing platform. Therefore, several methods have been reported for developing homogeneous metal/metal oxide nanostructures thin layer on the conducting polymer surfaces. This review will introduce the fabrications of different conducting polymers nanostructures and their composites with different shapes. We will exhibit the different techniques that can be used to develop conducting polymers nanostructures and to investigate their chemical, physical and topographical effects. Among the various biosensors, we will focus on conducting polymer-integrated electrochemical biosensors for monitoring important biological targets such as DNA, proteins, peptides, and other biological biomarkers, in addition to their applications as cell-based chips. Furthermore, the fabrication and applications of the molecularly imprinted polymer-based biosensors will be addressed in this review.

scholarly journals Prospects of Organic Conducting Polymer Modified Electrodes: Enzymosensors

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Ravindra P. Singh
Keyword(s):  
Public Health ◽  
Aqueous Solution ◽  
Conducting Polymer ◽  
Modified Electrodes ◽  
High Sensitivity ◽  
Biological Molecules ◽  
Electrochemical Biosensors ◽  
Preparation Methods ◽  
Neutral Aqueous Solution ◽  
Polymer Modified Electrodes

Organic conducting polymer modified electrodes (OCPMEs) have emerged as potential candidates for electrochemical biosensors due to their easy preparation methods along with unique properties, like stability in air and being compatible with biological molecules in a neutral aqueous solution. OCPMEs are playing an important role in the improvement of public health and environment for the detection of desired analytes with high sensitivity and specificity. In this paper, we highlight the prospects of OCMEs-based electrochemical enzymosensors.

Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

2020 ◽  
Author(s):  
Shubham Deolka ◽  
Orestes Rivada Wheelaghan ◽  
Sandra Aristizábal ◽  
Robert Fayzullin ◽  
Shrinwantu Pal ◽  
...  
Keyword(s):  
Alkyl Group ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Terminal Alkyne ◽  
Alkyl Aryl ◽  
Metal Metal ◽  
The Stability ◽  
Selective Formation ◽  
Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

scholarly journals Exosome-derived noncoding RNAs in gastric cancer: functions and clinical applications

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiao-Huan Tang ◽  
Ting Guo ◽  
Xiang-Yu Gao ◽  
Xiao-Long Wu ◽  
Xiao-Fang Xing ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Noncoding Rnas ◽  
Tumour Microenvironment ◽  
Clinical Applications ◽  
Biological Molecules ◽  
Biological Functions ◽  
Membrane Structures ◽  
Chemical Substances ◽  
Expression Levels ◽  
The Stability

AbstractExosomes are a subpopulation of the tumour microenvironment (TME) that transmit various biological molecules to promote intercellular communication. Exosomes are derived from nearly all types of cells and exist in all body fluids. Noncoding RNAs (ncRNAs) are among the most abundant contents in exosomes, and some ncRNAs with biological functions are specifically packaged into exosomes. Recent studies have revealed that exosome-derived ncRNAs play crucial roles in the tumorigenesis, progression and drug resistance of gastric cancer (GC). In addition, regulating the expression levels of exosomal ncRNAs can promote or suppress GC progression. Moreover, the membrane structures of exosomes protect ncRNAs from degradation by enzymes and other chemical substances, significantly increasing the stability of exosomal ncRNAs. Specific hallmarks within exosomes that can be used for exosome identification, and specific contents can be used to determine their origin. Therefore, exosomal ncRNAs are suitable for use as diagnostic and prognostic biomarkers or therapeutic targets. Regulating the biogenesis of exosomes and the expression levels of exosomal ncRNAs may represent a new way to block or eradicate GC. In this review, we summarized the origins and characteristics of exosomes and analysed the association between exosomal ncRNAs and GC development.

Novel Fiber-Optic Sensing System for Detection of Methane

2013 ◽  
Vol 562-565 ◽  
pp. 1008-1015 ◽  
Author(s):  
Shu Tao Wang ◽  
Peng Wei Zhang ◽  
Quan Min Zhu
Keyword(s):  
Fiber Optic ◽  
Detection System ◽  
Step Motor ◽  
Harmonic Detection ◽  
Distributed Feedback Laser ◽  
Gas Cell ◽  
Response Characteristics ◽  
The Stability ◽  
Application Fields ◽  
Methane Detection

Based on DFBLD (Distributed Feedback Laser Diode) and harmonic detection technique, a novel fiber-optic methane detection system is constructed. The system can be applied to broad-range concentration detection of methane. Based on the approximation express of the law of Beer-Lambert, detection of methane with various concentration from 0% to 20% is completed using subtraction of background and ratio processing method, as the atmosphere surroundings are treated as background noise. The direct absorption spectra for various concentration is measured using GRIN gas cell, combined with DFBLD. The R5 line of the 2v3 band of methane is selected as the absorption peak. The system is tested online during gas mixing process and the linear relationship between system indication and concentration variation is validated. Also the stability and dynamic response characteristics are confirmed by the experiments. The sensitivity of the system can be adjusted according to the concentration level of various field environments by changing the prism distance using step motor. In the range of 0% to 20% the sensitivity of methane detection can arrive at 0.001%. So the system can be applied to various application fields and adopted as monitoring instruments for coalmine tunnel and natural pipeline.

Controlled release of biological molecules from conducting polymer modified electrodes

1994 ◽  
Vol 368 (1-2) ◽  
pp. 329-332 ◽  
Author(s):  
Myoungho Pyo ◽  
Gabrielle Maeder ◽  
Robert T. Kennedy ◽  
John R. Reynolds
Keyword(s):  
Controlled Release ◽  
Conducting Polymer ◽  
Modified Electrodes ◽  
Biological Molecules ◽  
Polymer Modified Electrodes

Hierarchical flowerlike metal/metal oxide nanostructures derived from layered double hydroxides for catalysis and gas sensing

2017 ◽  
Vol 5 (45) ◽  
pp. 23999-24010 ◽  
Author(s):  
Xiao Wang ◽  
Ruya Cao ◽  
Shouwei Zhang ◽  
Peiyu Hou ◽  
Ruxia Han ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Layered Double Hydroxides ◽  
Gas Sensing ◽  
Catalytic Reduction ◽  
Oxide Nanostructures ◽  
Metal Metal ◽  
Metal Oxide Nanostructures ◽  
Double Hydroxides

Peony-like Co/Al2O3 and Co3O4/Al2O3 composites were fabricated using CoAl–LDHs as self-sacrificial templates and exhibited remarkable catalytic reduction and gas sensing abilities.

Sinusoidal AC-induced electrohydrodynamic direct-writing nanofibers on insulating collector

2021 ◽  
pp. 2140009
Author(s):  
Huatan Chen ◽  
Guoyi Kang ◽  
Jiaxin Jiang ◽  
Juan Liu ◽  
Xiang Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Flexible Electronics ◽  
Direct Writing ◽  
Printing Process ◽  
Ac Electric Field ◽  
Jet Printing ◽  
Voltage Frequency ◽  
Fiber Deposition ◽  
The Stability ◽  
Application Fields

Printing orderly patterns on the insulating collector is the key for the development and application of flexible electronics. However, electrospinning on the insulating collector still has the problem of unstable jet due to the charge accumulation. The alternating current (AC)-induced electrohydrodynamic direct-writing (EDW) technology is a good way to decrease the interferences of charge repulsion, which is beneficial to printing orderly micro/nanostructures on the insulating collector. In this work, the sinusoidal AC-induced EDW is used to enhance the stability of charged jet and the deposition behaviors under AC electric field are also studied. The reciprocation transferring of charges induced by the AC electric field decreased the density of the accumulating charges on the insulating collector. The effect of AC electric field parameters on the direct-written micro/nanostructures are investigated to optimize the printing process. As the voltage peak increases, the fiber deposition bandwidth shows a trend of decreasing first and then increasing. Increasing the voltage frequency appropriately is beneficial to decrease the bandwidth of fiber deposition and to increase the stability of the jet. By improving the stability and controllability of the jet printing process, precise micro/nanopatterns can be direct-written on the insulating collector. This research provides a good foundation for expanding the application fields of EDW.

Study and modeling of mechanisms of cholinesterasis reactions in order to improve their catalytic properties in the neutralization reactions of organophosphorous compounds

2020 ◽  
pp. 134-174
Author(s):  
Sergey Varfolomeev ◽  
Bella Grigorenko ◽  
Sofya Lushchekina ◽  
Patrick Masson ◽  
Galina Mahaeva ◽  
...  
Keyword(s):  
First Generation ◽  
Organophosphorus Compounds ◽  
Protein Molecule ◽  
Catalytic Antibodies ◽  
High Rate ◽  
Biological Targets ◽  
Organophosphorous Compounds ◽  
Rate Of Hydrolysis ◽  
The Stability ◽  
Hydrolysis Of

“Biocleaners” or “bioscavengers” are biological objects (enzymes, catalytic antibodies) that are capable of binding and/or hydrolyzing organophosphorus compounds (OPC). Their use seems to be the most effective alternative to traditional antidotes to neutralize or detoxify OPC. The introduction of bioscavengers allows neutralizing toxicant molecules in the bloodstream before they reach their biological targets, thereby providing protection against poisoning. Bioscavengers of the first-generation neutralized OPC molecules by stoichiometrically binding to them. The safety and efficacy of human butyrylcholinesterase (BChE) for protecting against OPC poisoning has been shown. However, the stoichiometric neutralization of OPC requires the introduction of a huge amount of expensive biopharmaceuticals. Catalytic bioscavengers that hydrolytically neutralize OPC were introduced at a much lower dose to achieve the same degree of effectiveness. The most effective catalytic bioscavengers are enzymes. The most promising enzymes are artificial mammalian paraoxonase mutants and bacterial phosphotriesterases. However, studies of other enzymes, such as prolidases, oxidases, artificial mutants of cholinesterases and carboxyl esterases and catalytic antibodies are actively ongoing. Since OPC are pseudosubstrates of cholinesterases (ChEs), a detailed description of the mechanisms of inhibition, dealkylation, and spontaneous reactivation of phosphorylated ChEs is critical for the development of ChEs mutants with a high rate of hydrolysis of OPC. The review presents an analysis of different views on the mechanisms of interaction of ChEs with OPC, discusses the possible directions of creating effective catalytic biological traps based on BChE and changes in their mechanism of action as compared to the native enzyme. A separate section is devoted to the effect of mutations, both polymorphic and artificial, on the stability of the protein molecule of BChE.

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