Multielement Electrochemical Sensors for Trace Metal Analysis in Aqueous Solutions PDF Download

Author: Stevan Bauer Saban
Publisher:
ISBN:
Category : Electrochemical sensors
Languages : en
Pages : 336

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Author: Yuanyuan Yang
Publisher:
ISBN:
Category : Chemistry, Analytic
Languages : en
Pages : 139

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Book Description
Detection of trace metals has great importance in environmental and biological applications. While traditional electrochemical techniques have played critical roles in this field, their usefulness is limited by temporal resolution, Hg toxicity and stability concerns. Recently, we developed a method using fast-scan cyclic voltammetry (FSCV) at carbon-fiber microelectrodes (CFMs) to achieve rapid measurement of metal ions with high sensitivity, selectivity, and stability. Through optimizations this method showed strengths in real-time trace metal analysis. Analytical selectivity was improved via covalent functionalization on CFMs. We employed diazonium electrochemical reduction followed by click chemistry to create robust covalent attachments. We showcased its application through grafting Cu(II) ionophores onto CFMs. The selectivity was further reinforced via inhibition of other species' adsorption at surface oxygen groups. This stepwise functionalization approach served as a universal platform for elevating CFMs' selectivity, while retaining sensitivity, response, stability, and lifetime. In parallel work, pyrolyzed photoresist film (PPF) microelectrode arrays (MEAs) were fabricated to extend the borderlines of FSCV towards simultaneous multi-analyte analysis. The PPF MEAs maintained CFM's carbon-fiber structures but provided more sensing channels. We employed a two-step pyrolysis process and a dual oxygen plasma treatment to improve fabrication repeatability, surface reactivity, and spatial geometry. Our technique has evident potential to achieve real-time simultaneous detection of various electroactive molecules and be employed for numerous applications in complex biological and environmental systems.

Author: Pierre Fabry
Publisher: John Wiley & Sons
ISBN: 111860010X
Category : Science
Languages : en
Pages : 266

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Book Description
This book reviews the state of art in the field of chemical sensors for analyses of ionic or molecular species dissolved in liquid media, mainly in aqueous solutions. The transduction of such devices is based on chemical, biological and physical phenomena. The fundamental phenomena involved in these sensors are described in the different chapters by specialists having a good expertise in the field. Numerous recent bibliographic references are given. Most of the devices could be miniaturised using modern technologies allowing a fabrication on a large scale, for a mass production at low cost. Moreover, such devices could open the field of applications in a near future (environmental, biomedical, food industries, domotic and automotive applications etc.).

Author: Lukasz Sztaberek
Publisher:
ISBN:
Category : Electrochemical sensors
Languages : en
Pages : 272

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Book Description
The specific goal of this project is to utilize novel microfabrication techniques to build small, stand-alone, and remotely controlled systems that will use anodic stripping voltammetry (ASV) as a sensing technique. ASV is known to be one of the most sensitive methods, and it has been widely applied for decades to analysis of trace amounts of heavy metals such as As, Cu, Pb, and Cd in aqueous solutions. Hence, it has been chosen as a model technique to demonstrate this concept. This approach not only provides accurate measurements at the parts per billion (ppb) concentration level, but also does not require complex and expensive instrumentation. In our work we have been investigating how microfabrication techniques could be used to improve performance of remote monitoring systems. In particular, several features have been tested to provide maximum life span of our sensors. These features include: integration of all electrodes (working, reference and counter) on one single chip, placing redundant electrodes on the chip, and also attempts at electrode modification and regeneration. It is important to be able to monitor the quality of drinking water against pollution and the addition of toxic substances. That insures safety of water storage and distribution systems. Worldwide, there are over billion of people who live without the access to safe drinking water and almost two and a half billion of people without basic sanitation. It was demonstrated, that using microfabrication techniques we were able to create an ASV system performing as planned in buffered solutions for metals such as cadmium, copper or lead. Designed chips had multiple sensing electrodes that performed very similarly. Additionally, successful modifications of electrodes, e.g. with AgCl, Bi or Nafion were demonstrated. In Chapter IV some future directions on how to make the sensor perform better are given.

Author: Samuel Mason Rosolina
Publisher:
ISBN:
Category : Cadmium
Languages : en
Pages : 200

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Book Description
The work in this dissertation focuses on the detection and analysis of trace chemicals in biological and environmental samples. Methods for the electrochemical detection of heavy metals Cd(II) [cadmium] and Pb(II) [lead], and the catalytic metal Pd(II) [palladium] in pharmaceutical ingredients have been optimized without the necessity of sample pretreatment. The metals can be analyzed simultaneously as well as individually, and the study includes the first known instance of the use of anodic stripping voltammetry (ASV) to detect metals in dimethyl sulfoxide (DMSO) solutions. Another method, based on ASV, has been optimized and evaluated for the purpose of mercury(II) analysis in a representative active pharmaceutical ingredient (API) and excipient. A pyridine-functionalized thin film has been fabricated to selectively preconcentrate hexavalent chromium [Cr(VI)] anions for electrochemical detection. Glassy carbon electrodes were modified through physical deposition of single-walled carbon nanotubes (SWNTs) on the electrode surface, followed by electrochemical deposition of a sol-gel containing a 2-pyridine functional group. The use of SWNTs has increased sensitivity for Cr(VI) detection in aqueous solutions, providing a detection limit of 0.3 μg L−1 (micrograms per liter). Two new processes to pretreat blood samples have been developed. The treatments are based on a Fenton-like advanced oxidation process (AOP). The first method is performed with a simple convection oven over a period of five hours, while the second uses microwave irradiation for six minutes. These novel methods allow for either cost-effective pretreatment through the use of the common lab oven, or time savings through the use of the synthesis microwave. The pretreated biological samples were further analyzed via anodic stripping for quantification of copper in the whole blood. A novel, disposable, Bi (bismuth)-based colorimetric sensor was developed for the detection of toxic hydrogen sulfide (H2S) gas. Using a simple laboratory setup to generate the H2S in a total volume of 1.35 L (liters), the sensor was able to qualitatively detect the analyte down to 30 ppb (parts per billion), indicating its ability to be used in industrial settings and manufactured into an inexpensive product for the determination of bad breath.

Author: Ligia Maria Moretto
Publisher: Springer
ISBN: 1493906763
Category : Science
Languages : en
Pages : 714

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Book Description
This book presents an exhaustive overview of electrochemical sensors and biosensors for the analysis and monitoring of the most important analytes in the environmental field, in industry, in treatment plants and in environmental research. The chapters give the reader a comprehensive, state-of-the-art picture of the field of electrochemical sensors suitable to environmental analytes, from the theoretical principles of their design to their implementation, realization and application. The first three chapters discuss fundamentals, and the last three chapters cover the main groups of analytes of environmental interest.

Author: Ligia Maria Moretto
Publisher: Springer
ISBN: 1493913018
Category : Science
Languages : en
Pages : 455

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Book Description
This book discusses in detail the analysis and monitoring of the most important analytes in the environmental field. It also reviews the implementation, realization and application of sensor designs mentioned in the first volume of this set, dividing the coverage into global parameters, sensors of organics and sensors of inorganics.

Author: Mambo Moyo
Publisher:
ISBN:
Category : Biosensors
Languages : en
Pages : 310

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Book Description
Discusses the main aim of studies conducted in this thesis was to develop an electrochemical HRP/MT-MWCNT biosensor and to explore its application for the sensitive and rapid determination of trace metal ions in aqueous solution based on inhibition principle. The maize tassel-multiwalled carbon nanotube (MT-MWCNT) composite has been used as a matrix for physical adsorption of horseradish peroxidase (HRP) onto the surface of a glassy carbon electrode through electrostatic interactions. The HRP/MT-MWCNT biosensor was applied for the detection of Zn2+ in aqueous solution. The biosensor designed was able to determine Zn2+ in the range of 0.35 - 12 mg/L with a detection limit of 7.5 pg/L. The inhibition was found to be reversible and uncompetitive when data were modeled using the Dixon and Cornish-Bowden plots. The biosensor was found to have good repeatability, reproducibility and high selectivity. The developed biosensor can be used to detect other HRP inhibiting trace metal ions.

Author: Ligia Maria Moretto
Publisher:
ISBN: 9781493913022
Category :
Languages : en
Pages : 472

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Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 990

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.