scholarly journals Colorimetric Detection of Mercury Ions in Water with Capped Silver Nanoprisms

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1533 ◽  
Author(s):  
Fouzia Tanvir ◽  
Atif Yaqub ◽  
Shazia Tanvir ◽  
Ran An ◽  
William A. Anderson
Keyword(s):  
Detection Limit ◽  
Coal Combustion ◽  
Matrix Effects ◽  
Colorimetric Detection ◽  
Industrial Processes ◽  
Rapid Testing ◽  
Mercury Ions ◽  
Reagent Solution ◽  
Testing Methods ◽  
Silver Nanoprisms

The emission of mercury (II) from coal combustion and other industrial processes may have impacts on water resources, and the detection with sensitive but rapid testing methods is desirable for environmental screening. Towards this end, silver nanoprisms were chemically synthesized resulting in a blue reagent solution that transitioned towards red and yellow solutions when exposed to Hg2+ ions at concentrations from 0.5 to 100 µM. A galvanic reduction of Hg2+ onto the surfaces is apparently responsible for a change in nanoprism shape towards spherical nanoparticles, leading to the change in solution color. There were no interferences by other tested mono- and divalent metal cations in solution and pH had minimal influence in the range of 6.5 to 9.8. The silver nanoprism reagent provided a detection limit of approximately 1.5 µM (300 µg/L) for mercury (II), which compared reasonably well with other reported nanoparticle-based techniques. Further optimization may reduce this detection limit, but matrix effects in realistic water samples require further investigation and amelioration.

scholarly journals Colorimetric Detection of Mercury Ions in Water with Capped Silver Nanoprisms

2019 ◽  
Author(s):  
Fouzia Tanvir ◽  
Atif Yaqub ◽  
Shazia Tanvir ◽  
Ran An ◽  
William A. Anderson
Keyword(s):  
Detection Limit ◽  
Coal Combustion ◽  
Colorimetric Detection ◽  
Industrial Processes ◽  
Rapid Testing ◽  
Mercury Ions ◽  
Reagent Solution ◽  
Testing Methods ◽  
Silver Nanoprisms ◽  
Local Impact

The emission of mercury (II) from coal combustion and other industrial processes continues to be a concern and have local impact on water resources.  The detection of these ions in water with sensitive but rapid testing methods is desirable for environmental screening and fieldwork.  Nanoparticles of various chemistries have shown promise for this purpose, as they can be used in simple colorimetric analyses. Silver nanoprisms were chemically synthesized resulting in a blue reagent solution, that transitioned towards yellow and colorless solutions when exposed to Hg2+ ions at various concentrations. A rapid galvanic reduction of Hg2+ onto the nanoprism surfaces is apparently responsible for a change in shape towards spherical nanoparticles, leading to the change in color. There were no interferences by other metal ions in solution, and pH had minimal effect in the range of 6.5 to 9.8. The silver nanoprism reagent provided a detection limit of approximately 0.5 µM (100 µg/L) for mercury (II), which compares favorably with other nanoparticle-based techniques. Further optimization may reduce this detection limit.

Silver Nanoprism for Selective and Sensitive Detection of Hg+2 Ions

2021 ◽  
Vol 21 (12) ◽  
pp. 6094-6100
Author(s):  
Avneesh Mittal ◽  
Komal Gupta ◽  
Balaram Pani ◽  
Gulshan Kumar ◽  
Gopala Ram Bhadu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Surface Plasmon Resonance ◽  
Detection Limit ◽  
Surface Plasmon ◽  
Water Samples ◽  
High Performance ◽  
Colorimetric Detection ◽  
Silver Nanoprisms ◽  
Highly Sensitive ◽  
Varied Concentration

In this article, we propose high-performance colorimetric detection of Hg+2 using silver nanoprisms. The spherical and triangular AgNPs were synthesized using varied concentration of NaBH4. Pristine AgNPs without any further modification were used for the detection of various metal ions including Hg2+, Pb2+, Cl−, Cd2+, Co2+, Cu2+, Ba2+, Pb2+, Cr3+, Cr2O2−7 , Fe2+, Fe3+ etc. AgNPs were not only selective in detecting the ions of Cl− and Hg+2 ions but also highly sensitive. Minimum detection limit was observed to be as low as 10−7 ppm for both Hg+2 and Cl−. Water samples collected from various locations detected for the presence of various heavy metals. Silver nanoprisms owing to their surface plasmon resonance exhibit highly selective tendency towards detection against Hg+2.

scholarly journals The determination of N-methylcarbamate pesticides using enzyme immunoassays with chemiluminescent detection

2004 ◽  
Vol 22 (SI - Chem. Reactions in Foods V) ◽  
pp. S280-S282 ◽  
Author(s):  
B. Mičková ◽  
P. Rauch ◽  
A. Montoya ◽  
E. Ferri ◽  
F. Fini ◽  
...  
Keyword(s):  
Detection Limit ◽  
Matrix Effects ◽  
Colorimetric Detection ◽  
Fruit Juices ◽  
Analytical Performance ◽  
Experimental Comparison ◽  
Enzyme Immunoassays ◽  
Chemiluminescent Detection ◽  
Concentration Levels

In the present work, enzyme-linked immunosorbent assays (ELISAs) with chemiluminescent detection for the determination of carbofuran, carbaryl and methiocarb were developed and the analytical parameters of these assays were compared with those of ELISAs with colorimetric detection. The sensitivity of immunochemical methods was expressed as detection limit, linear working range, and I<sub>50</sub> value. In comparison with colorimetric ELISA, the ability of the chemiluminescent reagents to detect lower concentrations of HRP allowed to decrease the optimal antibody and conjugate concentrations and to reach better analytical parameters. The experimental comparison of the analytical performance of the ELISAs was carried out by analysing simply diluted fruit juices, spiked at different concentration levels with the above mentioned pesticides. Recovery values for both ELISAs were around 100% and no matrix effects were observed when fruit juices were diluted 1:20 or more.

scholarly journals Development, characterization and first deployment of an improved online reactive oxygen species analyzer

2018 ◽  
Vol 11 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Jun Zhou ◽  
Emily A. Bruns ◽  
Peter Zotter ◽  
Giulia Stefenelli ◽  
André S. H. Prévôt ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Detection Limit ◽  
Atmospheric Aerosols ◽  
Half Life ◽  
Matrix Effects ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Wood Combustion ◽  
Storage Duration ◽  
High Concentrations

Abstract. Inhalation of atmospheric particles is linked to human diseases. Reactive oxygen species (ROS) present in these atmospheric aerosols may play an important role. However, the ROS content in aerosols and their formation pathways are still largely unknown. Here, we have developed an online and offline ROS analyzer using a 2′,7′-dichlorofluorescin (DCFH) based assay. The ROS analyzer was calibrated with H2O2 and its sensitivity was characterized using a suite of model organic compounds. The instrument detection limit determined as 3 times the noise is 1.3 nmol L−1 for offline analysis and 2 nmol m−3 of sampled air when the instrument is operated online at a fluorescence response time of approximately 8 min, while the offline method detection limit is 18 nmol L−1. Potential interferences from gas-phase O3 and NO2 as well as matrix effects of particulate SO42− and NO3− were tested, but not observed. Fe3+ had no influence on the ROS signal, while soluble Fe2+ reduced it if present at high concentrations in the extracts. Both online and offline methods were applied to identify the ROS content of different aerosol types, i.e., ambient aerosols as well as fresh and aged aerosols from wood combustion emissions. The stability of the ROS was assessed by comparing the ROS concentration measured by the same instrumentation online in situ with offline measurements. We also analyzed the evolution of ROS in specific samples by conducting the analysis after storage times of up to 4 months. The ROS were observed to decay with increasing storage duration. From their decay behavior, ROS in secondary organic aerosol (SOA) can be separated into short- and long-lived fractions. The half-life of the short-lived fraction was 1.7 ± 0.4 h, while the half-life of the long-lived fraction could not be determined with our uncertainties. All these measurements showed consistently that on average 60 ± 20 % of the ROS were very reactive and disappeared during the filter storage time. This demonstrates the importance of a fast online measurement of ROS.

scholarly journals Enhancement of the Peroxidase-Like Activity of Iodine-Capped Gold Nanoparticles for the Colorimetric Detection of Biothiols

Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 113 ◽  
Author(s):  
Chia-Chen Chang ◽  
Tsz-Lian Hsu ◽  
Chie-Pein Chen ◽  
Chen-Yu Chen
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Detection Limit ◽  
Enzymatic Activity ◽  
Catalytic Properties ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Synergetic Effect ◽  
Vis Spectroscopy ◽  
Wide Range

A colorimetric assay was developed for the detection of biothiols, based on the peroxidase-like activity of iodine-capped gold nanoparticles (AuNPs). These AuNPs show a synergetic effect in the form of peroxidase-mimicking activity at the interface of AuNPs, while free AuNPs and iodine alone have weak catalytic properties. Thus, iodine-capped AuNPs possess good intrinsic enzymatic activity and trigger the oxidation of 3,3’,5,5’-tetramethylbenzidine (TMB), leading to a change in color from colorless to yellow. When added to solution, biothiols, such as cysteine, strongly bind to the interface of AuNPs via gold-thiol bonds, inhibiting the catalytic activity of AuNPs, resulting in a decrease in oxidized TMB. Using this strategy, cysteine could be linearly determined, at a wide range of concentrations (0.5 to 20 μM), with a detection limit of 0.5 μM using UV-Vis spectroscopy. This method was applied for the detection of cysteine in diluted human urine.

Ultrasensitive colorimetric detection of Hg2+ ions based on enhanced catalytic performance of gold amalgam dispersed in channels of rose petals

The Analyst ◽  
2019 ◽  
Vol 144 (4) ◽  
pp. 1205-1209 ◽  
Author(s):  
Chi Zhang ◽  
Caiyun Kong ◽  
Qingyun Liu ◽  
Zhengbo Chen
Keyword(s):  
Gold Nanoparticles ◽  
Pore Structure ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Catalytic Performance ◽  
Mercury Ions ◽  
Colorimetric Sensing ◽  
Rose Petals

We herein present a simple, low-cost, and ultrasensitive colorimetric sensing strategy for the detection of mercury ions (Hg2+) that takes advantage of the natural pore structure in rose petals to encapsulate gold nanoparticles (AuNPs).

scholarly journals Temperature stability of mercury compounds in solid substrates

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Matej Sedlar ◽  
Majda Pavlin ◽  
Arkadij Popovič ◽  
Milena Horvat
Keyword(s):  
Coal Combustion ◽  
Temperature Stability ◽  
Absorption Spectrometry ◽  
Industrial Processes ◽  
Solid Materials ◽  
Mercury Compounds ◽  
Solid Substrates ◽  
Cold Vapour ◽  
The Subject ◽  
Type Mass

AbstractThe major aim of the newly adopted Mercury Convention is to reduce global mercury (Hg) emissions to the environment. In high temperature industrial processes, including coal combustion, Hg compounds present as impurities in solid materials are decomposed and evaporated leading to the emission of Hg to the atmosphere. The behaviour of different Hg compounds and their mixtures during heating have been the subject of numerous studies, and is the topic of the present work. Controlled heating can be used to fractionate Hg compounds in solid substrates, offering the possibility of identification and quantification of Hg compounds. In the attempt to develop a method for temperature fractionation of Hg, experiments were conducted with pure Hg compounds, and the compounds mixed with different substrates (SiO2 and CaSO4 • 2H2O), for calibration purposes. Detection was performed by two methods, namely Cold Vapour Atomic Absorption Spectrometry (CV AAS) with Zeeman background correction, and Nier-type Mass Spectrometry with a Knudsen cell (MS). Further investigation is in process.

Colorimetric detection of catalase and catalase-positive bacteria (E. coli) using silver nanoprisms

2016 ◽  
Vol 8 (36) ◽  
pp. 6625-6630 ◽  
Author(s):  
Lili Zhao ◽  
Julia Wiebe ◽  
Rabia Zahoor ◽  
Sladjana Slavkovic ◽  
Brian Malile ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalase Activity ◽  
Colorimetric Detection ◽  
E Coli ◽  
Silver Nanoprisms

The sensitivity of the formation of plasmonic silver nanoprisms to hydrogen peroxide is explored for the colorimetric detection of catalase activity in bacteria.

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