Bismuth-coated carbon electrodes for anodic stripping voltammetry
TL;DR: Stripping voltammetric measurements of microgram per liter levels of cadmium, lead, thallium, and zinc in nondeaerated solutions yielded well-defined peaks, along with a low background, following short deposition periods, indicating great promise to centralized and decentralized testing of trace metals.
Abstract: Bismuth-coated carbon electrodes display an attractive stripping voltammetric performance which compares favorably with that of common mercury-film electrodes. These bismuth-film electrodes are prepared by adding 400 μg/L (ppb) bismuth(III) directly to the sample solution and simultanously depositing the bismuth and target metals on the glassy-carbon or carbon-fiber substrate. Stripping voltammetric measurements of microgram per liter levels of cadmium, lead, thallium, and zinc in nondeaerated solutions yielded well-defined peaks, along with a low background, following short deposition periods. Detection limit of 1.1 and 0.3 ppb lead are obtained following 2- and 10-min deposition, respectively. Changes in the peak potentials (compared to those observed at mercury electrodes) offer new selectivity dimensions. Scanning electron microscopy sheds useful insights into the different morphologies of the bismuth deposits on the carbon substrates. The in situ bismuth-plated electrodes exhibit a wide accessible po...
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TL;DR: Recent Trends in Macro-, Micro-, and Nanomaterial-Based Tools and Strategies for Heavy-Metal Detection Gemma Aragay, Josefina Pons, and Arben Merkoc-i.
Abstract: Recent Trends in Macro-, Micro-, and Nanomaterial-Based Tools and Strategies for Heavy-Metal Detection Gemma Aragay, Josefina Pons, and Arben Merkoc-i* Nanobioelectronics & Biosensors Group, Institut Catal a de Nanotecnologia (CIN2, ICN-CSIC), 08193, Bellaterra, Barcelona, Spain Departament of Chemistry, Universitat Aut onoma de Barcelona, 08193, Bellaterra, Barcelona, Spain ICREA, Barcelona, Spain
1,136 citations
TL;DR: The fabrication and the performance of microfluidic paper-based electrochemical sensing devices are described and it is demonstrated that the microPEDs are capable of quantifying the concentrations of various analytes in aqueous solutions.
Abstract: This paper describes the fabrication and the performance of microfluidic paper-based electrochemical sensing devices (we call the microfluidic paper-based electrochemical devices, µPEDs). The µPEDs comprise paper-based microfluidic channels patterned by photolithography or wax printing, and electrodes screen-printed from conducting inks (e.g., carbon or Ag/AgCl). We demonstrated that the µPEDs are capable of quantifying the concentrations of various analytes (e.g., heavy-metal ions and glucose) in aqueous solutions. This low-cost analytical device should be useful for applications in public health, environmental monitoring, and the developing world.
851 citations
TL;DR: This review summarizes the latest advances in this emerging field of "bio-integrated" technologies in a comprehensive manner that connects fundamental developments in chemistry, material science, and engineering with sensing technologies that have the potential for widespread deployment and societal benefit in human health care.
Abstract: Bio-integrated wearable systems can measure a broad range of biophysical, biochemical, and environmental signals to provide critical insights into overall health status and to quantify human performance. Recent advances in material science, chemical analysis techniques, device designs, and assembly methods form the foundations for a uniquely differentiated type of wearable technology, characterized by noninvasive, intimate integration with the soft, curved, time-dynamic surfaces of the body. This review summarizes the latest advances in this emerging field of “bio-integrated” technologies in a comprehensive manner that connects fundamental developments in chemistry, material science, and engineering with sensing technologies that have the potential for widespread deployment and societal benefit in human health care. An introduction to the chemistries and materials for the active components of these systems contextualizes essential design considerations for sensors and associated platforms that appear in f...
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TL;DR: This review presents various electrochemical detection techniques for heavy metal ions those are user friendly, low cost, provides on-site and real time monitoring as compared to other spectroscopic and optical techniques.
660 citations
Cites background from "Bismuth-coated carbon electrodes fo..."
...As it is well reported, bismuth electrodes offer a well-defined, undistorted, and highly reproducible stripping response, excellent resolution of neighbouring peaks, high hydrogen evolution, wide linear dynamic range, with signal-to-background characteristics comparable to those of common mercury electrodes (Wang et al., 2000)....
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...…offer a well-defined, undistorted, and highly reproducible stripping response, excellent resolution of neighbouring peaks, high hydrogen evolution, wide linear dynamic range, with signal-to-background characteristics comparable to those of common mercury electrodes (Wang et al., 2000)....
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...Another electrode that has shown promising results for ASV is a Bi-modified electrode (Wang et al., 2000; Wang et al., 2001a; Wang et al., 2001b; Flechsig et al., 2002; Pauliukaite et al., 2004)....
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TL;DR: In this paper, the development, behavior, scope and prospects of bismuth electrodes for stripping-based electrochemical measurements of trace metals are reviewed, with applications ranging from continuous remote sensing to single-use measurements.
Abstract: For many years mercury electrodes were the transducer of choice in stripping voltammetry of trace metals owing to their high sensitivity, reproducibility, and renewability. However, because of the toxicity of mercury, alternative (‘environmentally friendly’) electrode materials are highly desired for both centralized and field applications. Recently introduced bismuth electrodes offer a very attractive alternative to commonly used mercury electrodes. Such electrodes display well-defined, undistorted and highly reproducible response, favorable resolution of neighboring peaks, high hydrogen evolution, with good signal-to-background characteristics comparable to those of common mercury electrodes. The attractive stripping behavior of bismuth electrodes reflects the ability of bismuth to form ‘fused’ multicomponent alloys with heavy metals. Bismuth stripping electrodes thus hold great promise for decentralized metal testing, with applications ranging from continuous remote sensing to single-use measurements. Fundamental studies aimed at understanding the behavior of bismuth film electrodes should lead to rational preparation and operation of reliable alternative (‘non–mercury’) stripping electrodes that would have a major impact upon electroanalysis of trace metals. This article reviews the development, behavior, scope and prospects of bismuth electrodes for stripping-based electrochemical measurements of trace metals.
514 citations
References
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TL;DR: In this paper, an anodic stripping technique is described in which a very thin mercury film is formed on a polished glassy carbon substrate by adding mercuric nitrate to the sample solution and electrodepositing mercury and trace metals simultaneously.
371 citations
TL;DR: In this article, the characterization and separate electrochemical determinations of Cu2+ and Hg2+ directly on a microlithographically fabricated array of iridium ultramicroelectrodes (Ir-UMEA) were reported.
Abstract: In this paper, we report for the first time the characterization and separate electrochemical determinations of Cu2+ and Hg2+ directly on a microlithographically fabricated array of iridium ultramicroelectrodes (Ir-UMEA). Square-wave anodic stripping voltammetry was used to optimize experimental parameters such as supporting electrolyte, square-wave frequency, and deposition time and potential. Reproducible stripping peaks were obtained for solutions containing low parts per billion (ppb) concentrations of either metal. Excellent linearity was obtained for Cu2+ in the 20−100 ppb range and for Hg2+ in the 1−10 ppb range when the bare iridium substrate was used. Detection limits were calculated to be 1 ppb (0.1 M KNO3 and 0.1 M HClO4, deposition time 180 s) and 5 ppb (0.1 M H2SO4, deposition time 120 s) for Cu2+ (S/N = 3) and 85 ppt for Hg2+ (deposition time 600 s). The experimental detection limits were determined to be 5 ppb for Cu2+ (deposition time 180 s) and 100 ppt for Hg2+ (deposition time 600 s). In...
196 citations
TL;DR: Stripping voltammetry is very suitable for ship-board and in-situ applications because of the portability, low cost and capability for automation of the voltammetric instrumentation as discussed by the authors.
185 citations
TL;DR: Various experimental parameters are optimized to allow convenient monitoring of micrograms per liter lead concentrations following short deposition periods and the highly stable response of these screen-printed electrodes makes them very attractive for both single-use and multiple applications.
Abstract: Gold-coated screen-printed electrodes offer reliable quantitation of trace lead in connection with potentiometric stripping analysis (PSA). Such replacement of mercury-based sensors, with gold-coated ones, avoids environmental contamination associated with the disposal of mercury electrodes in connection with large-scale screening for lead poisoning. The PSA operation obviates the need for oxygen removal, offers low background contributions, and minimizes surfactant interferences. Changes in the peak intensity and position (vs mercury-coated strips) offer new selectivity dimensions. Various experimental parameters are optimized to allow convenient monitoring of micrograms per liter lead concentrations following short deposition periods. Applicability to urine and drinking water samples is illustrated. The highly stable response of these screen-printed electrodes makes them very attractive for both single-use and multiple applications.
173 citations
TL;DR: In this article, the applications of chemically modified electrodes (CMEs) to the determination of trace amounts of metals and organic analytes are discussed, and the common feature of the CMEs reviewed is that prior to the voltammetric determination step the analyte is collected or accumulated onto the electrode.
Abstract: The applications of chemically modified electrodes (CMEs) to the determination of trace amounts of metals and organic analytes are discussed. The common feature of the CMEs reviewed is that prior to the voltammetric determination step the analyte is collected or accumulated onto the electrode. The accumulation step serves to preconcentrate the analytes from dilute solution, making their determination easier. It is analogous to the preconcentration step employed in stripping voltammetry at conventional electrodes. Trace analytes can be accumulated in several ways: ion-exchange, complexation, bioaccumulation, covalent attachment, and hydrophobic interaction accumulation schemes are discussed. Uses of CMEs in speciation analysis are outlined, and modified mercury-film electrodes and mercury films based on CMEs are discussed. Examples of the use of CMEs in the determination of trace metals [e.g., copper(II), lead(II), mercury(II), and silver(I) ions] and organic compounds are given.
154 citations