Efficient Microwave-Assisted Extraction of Nitrites from Cured Meat and Their Voltammetric Detection at Chemically Modified Electrodes Based on Hexamethyl-p-Terphenyl Poly(methylatedbenzimidazolium) Incorporating Nitrogen-Doped Graphite Nanoplatelets

We describe a fast and reliable procedure for the efficient extraction of nitrites in cured meat using microwave-assisted heat and report their in situ determination via voltammetry using an anion-exchanger ionene, hexamethyl-p-terphenyl poly(benzimidazolium) (HMT-PMBI), and nitrogen-doped graphite nanoplatelets (NGNPs). Cyclic voltammetry and chronoamperometry were utilized to evaluate the concentration of the redox mediator within the film and apparent diffusion coefficient. To investigate the suitability of the composite material for sensing applications, HMT-PMBI/NGNPs were tested for their detection of nitrite in bacon samples without the need of any pretreatments or dilutions. HMT-PMBI/NGNP coated electrodes showed enhanced sensitivity in the detection of nitrite ions in bacon with a limit of detection (LoD) of 0.64 µM, sensitivity 0.52 µA µM−1 cm−2, and operating in a linear range between 1–300 μM. The results highlight that the determination of nitrites in cured meat using microwave extraction is in good agreement with standard procedures such as the ISO 2918 and the AOAC International 973.31 methods.

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Quaternary phosphonium-based (TPQPCl)-ionomer/graphite nanoplatelets composite chemically modified electrodes: a novel platform for sensing applications

Journal of Materials Chemistry C ◽

10.1039/c8tc04967j ◽

2018 ◽

Vol 6 (48) ◽

pp. 13293-13304 ◽

Cited By ~ 5

Author(s):

Sandra Hernandez-Aldave ◽

Robert B. Kaspar ◽

Michael P. Letterio ◽

Afshin Tarat ◽

Yushan Yan ◽

...

Keyword(s):

Ascorbic Acid ◽

Amperometric Detection ◽

Modified Electrodes ◽

Chemically Modified Electrodes ◽

Graphite Nanoplatelets ◽

Chemically Modified ◽

Sensing Applications ◽

Sensing Platform ◽

Coated Electrodes

Ionomer (TPQPCl)/graphite nanoplatelet-coated electrodes are developed as a new sensing platform for amperometric detection of ascorbic acid.

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Voltammetry at Hexamethyl-P-Terphenyl Poly(Benzimidazolium) (HMT-PMBI)-Coated Glassy Carbon Electrodes: Charge Transport Properties and Detection of Uric and Ascorbic Acid

Sensors ◽

10.3390/s20020443 ◽

2020 ◽

Vol 20 (2) ◽

pp. 443

Author(s):

Rees ◽

Wright ◽

Holdcroft ◽

Bertoncello

Keyword(s):

Ascorbic Acid ◽

Uric Acid ◽

Vitamin C ◽

Anion Exchange ◽

Limit Of Detection ◽

Modified Electrodes ◽

Chemically Modified Electrodes ◽

Linear Range ◽

Chemically Modified ◽

Voltammetric Detection

We describe the voltammetric behavior of an anion-exchange membrane, hexamethyl-p-terphenyl poly(benzimidazolium) (HMT-PMBI). The anion-exchange properties of HMT-PMBI chemically modified electrodes were investigated using K4Fe(CN)6 and K2IrCl6 as redox probes. The permselectivity properties of HMT-PMBI chemically modified electrodes were ascertained using tris(2-2’)bipyridyl-ruthenium(II) chloride Ru(bpy)32+. Cyclic voltammetry and chronoamperometry were utilized to extract parameters such as the concentration of the redox mediators inside the films and the apparent diffusion coefficients. We found the concentration of K4Fe(CN)6 and K2IrCl6 redox species within HMT-PMBI-coated films to be on the order of 0.04–0.1 mol·dm−3, and values of Dapp ca. 10−10–10−9 cm2·s−1. To evaluate the possibility of using such a polymer coating in electroanalysis, HMT-PMBI-modified electrodes were utilized for the voltammetric detection of uric acid in artificial urine, Surine® and ascorbic acid in Vitamin C samples. The results showed that HMT-PMBI-coated electrodes can detect uric acid in Surine® with a limit of detection (LoD) of 7.7 µM, sensitivity of 0.14 µA·µM−1·cm−2, and linear range between 5 μM and 200 μM, whereas for Vitamin C tablets, the LoD is 41.4 µM, the sensitivity is 0.08 µA·µM−1·cm−2, and the linear range is between 25 μM and 450 μM.

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Electrochemical Detection of Endosulfan Using an AONP-PANI-SWCNT Modified Glassy Carbon Electrode

Materials ◽

10.3390/ma14040723 ◽

2021 ◽

Vol 14 (4) ◽

pp. 723

Author(s):

Kgotla K. Masibi ◽

Omolola E. Fayemi ◽

Abolanle S. Adekunle ◽

Amal M. Al-Mohaimeed ◽

Asmaa M. Fahim ◽

...

Keyword(s):

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Limit Of Detection ◽

Modified Electrodes ◽

Antimony Oxide ◽

Current Response ◽

Carbon Electrode ◽

Trace Detection ◽

Limit Of Quantification ◽

Walled Carbon Nanotubes

This report narrates the successful application of a fabricated novel sensor for the trace detection of endosulfan (EDS). The sensor was made by modifying a glassy-carbon electrode (GCE) with polyaniline (PANI), chemically synthesized antimony oxide nanoparticles (AONPs), acid-functionalized, single-walled carbon nanotubes (fSWCNTs), and finally, the AONP-PANI-SWCNT nanocomposite. The electrochemical properties of the modified electrodes regarding endosulfan detection were investigated via cyclic voltammetry (CV) and square-wave voltammetry. The current response of the electrodes to EDS followed the trend GCE-AONP-PANI-SWCNT (−510 µA) > GCE-PANI (−59 µA) > GCE-AONPs (−11.4 µA) > GCE (−5.52 µA) > GCE-fSWCNTs (−0.168 µA). The obtained results indicated that the current response obtained at the AONP-PANI-SWCNT/GCE was higher with relatively low overpotential compared to those from the other electrodes investigated. This demonstrated the superiority of the AONP-PANI-SWCNT-modified GCE. The AONP-PANI-SWCNT/GCE demonstrated good electrocatalytic activities for the electrochemical reduction of EDS. The results obtained in this study are comparable with those in other reports. The sensitivity, limit of detection (LoD), and limit of quantification (LoQ) of AONP-PANI-SWCNT/GCE towards EDS was estimated to be 0.0623 µA/µM, 6.8 µM, and 20.6 µM, respectively. Selectivity, as well as the practical application of the fabricated sensor, were explored, and the results indicated that the EDS-reduction current was reduced by only 2.0% when interfering species were present, whilst average recoveries of EDS in real samples were above 97%.

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Recent Advances in the Use of Transition-Metal Porphyrin and Phthalocyanine Complexes as Electro-Catalyst Materials on Modified Electrodes for Electroanalytical Sensing Applications

Solids ◽

10.3390/solids2020014 ◽

2021 ◽

Vol 2 (2) ◽

pp. 212-231

Author(s):

J. Antonio Cruz-Navarro ◽

Fabiola Hernández-García ◽

Luis Humberto Mendoza-Huizar ◽

Verónica Salazar-Pereda ◽

J. Ángel Cobos-Murcia ◽

...

Keyword(s):

Transition Metal ◽

Catalytic Properties ◽

Modified Electrodes ◽

Metal Porphyrin ◽

Water Contaminants ◽

Active Behavior ◽

Sensing Applications ◽

Redox Active ◽

Innovative Materials ◽

Solid Electrodes

Metalloporphyrins (MP) and metallophtalocyanines (MPc) are innovative materials with catalytic properties that have attracted attention for their application for diverse electrochemical purposes. The presence of metallic centers in their structure offers a redox-active behavior that is being applied in the design of solid electrodes for the quantification of biomolecules, water contaminants, and pharmaceuticals, among others. Herein, we collect the recent information about porphyrin and phthalocyanine complexes as modifiers of electrodes, and the important aspects of the design, characterization, and application of these electrodes.

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A Nanoplasmonic-Based Biosensing Approach for Wide-Range and Highly Sensitive Detection of Chemicals

Nanomaterials ◽

10.3390/nano11081961 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1961

Author(s):

Francesco Arcadio ◽

Luigi Zeni ◽

Aldo Minardo ◽

Caterina Eramo ◽

Stefania Di Di Ronza ◽

...

Keyword(s):

Optical Fibers ◽

Limit Of Detection ◽

Slab Waveguide ◽

Grating Pattern ◽

Transparent Substrate ◽

Synthetic Receptor ◽

Sensing Applications ◽

Wide Range ◽

Plastic Optical Fibers ◽

Highly Sensitive Detection

In a specific biosensing application, a nanoplasmonic sensor chip has been tested by an experimental setup based on an aluminum holder and two plastic optical fibers used to illuminate and collect the transmitted light. The studied plasmonic probe is based on gold nanograting, realized on the top of a Poly(methyl methacrylate) (PMMA) chip. The PMMA substrate could be considered as a transparent substrate and, in such a way, it has been already used in previous work. Alternatively, here it is regarded as a slab waveguide. In particular, we have deposited upon the slab surface, covered with a nanograting, a synthetic receptor specific for bovine serum albumin (BSA), to test the proposed biosensing approach. Exploiting this different experimental configuration, we have determined how the orientation of the nanostripes forming the grating pattern, with respect to the direction of the input light (longitudinal or orthogonal), influences the biosensing performances. For example, the best limit of detection (LOD) in the BSA detection that has been obtained is equal to 23 pM. Specifically, the longitudinal configuration is characterized by two observable plasmonic phenomena, each sensitive to a different BSA concentration range, ranging from pM to µM. This aspect plays a key role in several biochemical sensing applications, where a wide working range is required.

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Porous silicon membrane-modified electrodes for label-free voltammetric detection of MS2 bacteriophage

Biosensors and Bioelectronics ◽

10.1016/j.bios.2016.01.038 ◽

2016 ◽

Vol 80 ◽

pp. 47-53 ◽

Cited By ~ 25

Author(s):

Nekane Reta ◽

Andrew Michelmore ◽

Christopher Saint ◽

Beatriz Prieto-Simón ◽

Nicolas H. Voelcker

Keyword(s):

Porous Silicon ◽

Modified Electrodes ◽

Label Free ◽

Silicon Membrane ◽

Ms2 Bacteriophage ◽

Voltammetric Detection

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Total Fat Gravimetric Method Workflow in Portuguese Olives Using Closed-Vessel Microwave-Assisted Extraction (MAE)

Foods ◽

10.3390/foods10102364 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2364

Author(s):

João Gonçalo Lourenço ◽

Daniel Ettlin ◽

Inês Carrero Cardoso ◽

Jesus M. Rodilla

Keyword(s):

Limit Of Detection ◽

Gravimetric Method ◽

Reference Value ◽

Microwave Assisted Extraction ◽

Closed Vessel ◽

Limit Of Quantification ◽

Microwave Assisted ◽

Assisted Extraction ◽

Total Fat

A simple and rapid method for the quantitation of total fat in olive samples is designed, evaluated, and presented. This method is based on an innovative closed-vessel microwave-assisted extraction (MAE) technique. A method was designed for olives, and some figures of merits were evaluated: limit of detection (LOD), limit of quantification (LOQ) and expanded uncertainty (U). The data obtained in these experiences show that the workflow of the MAE method in a closed container is statistically equivalent to the other two methods, showing in this case better performance indicators (LOD = 0.02%, LOQ = 0.06%, and U = 15%). In addition, it is also demonstrated that the complete MAE method workflow allows the determination of total fat in a maximum of 12 analyses simultaneously for about 100 min in each run, which is the capacity of the rotor. This is a much better productivity when compared to the traditional Soxhlet-based method. Considering the sample workflow, the closed-vessel MAE method greatly simplifies sample handling, therefore minimizing sample loss during sample preparation and reducing analysis time. When MAE is compared to NIR-based methods, the advantage comes from there being no need for any type of calibration in the sample matrix. The MAE method itself can be used to determine the reference value for NIR calibration purposes. The results obtained for CRM using MAE were equivalent to the ones shown on the certificate.

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Laccase Electrochemical Biosensor Based on Graphene-Gold/Chitosan Nanocomposite Film for Bisphenol A Detection

Current Analytical Chemistry ◽

10.2174/1573411015666190117114804 ◽

2020 ◽

Vol 16 (5) ◽

pp. 570-579

Author(s):

Fuzi M. Fartas ◽

Jaafar Abdullah ◽

Nor A. Yusof ◽

Yusran Sulaiman ◽

Mohd I. Saiman ◽

...

Keyword(s):

Bisphenol A ◽

Electrochemical Biosensor ◽

Limit Of Detection ◽

Modified Electrodes ◽

Electrochemical Performances ◽

Carbon Electrode ◽

Screen Printed Carbon Electrode ◽

Laccase Enzyme ◽

Bisphenol A Detection ◽

Screen Printed

Background: Bisphenol A (BPA) is considered one of the most common chemicals that could cause environmental endocrine disrupting. Therefore, there is an increasing demand for simple, rapid and sensitive methods for BPA detection that result from BPA leaching into foods and beverages from storage containers. Herein, a simple laccase electrochemical biosensor was developed for the determination of BPA based on Screen-Printed Carbon Electrode (SPCE) modified graphenegold/ chitosan. The synergic effect of graphene-gold/chitosan nanocomposite as electrode modifier greatly facilitates electron-transfer processes between the electrolyte and laccase enzyme, thus leads to a remarkably improved sensitivity for bisphenol A detection. Methods: In this study, laccase enzyme is immobilized onto the Screen-Printed Carbon Electrode (SPCE) modified Graphene-Decorated Gold Nanoparticles (Gr-AuNPs) with Chitosan (Chit). The surface structure of nanocomposite was studied using different techniques including Field Emission Scanning Microscopy (FESEM), TRANSMISSION Electron Microscopy (TEM), Raman spectroscopy and Energy Dispersive X-ray (EDX). Meanwhile, the electrochemical performances of the modified electrodes were studied using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Results: The developed laccase biosensor offered excellent analytical performance for the detection of BPA with a sensitivity of 0.271 μA/μM and Limit of Detection (LOD) of 0.023 μM, respectively. Moreover, the constructed biosensor showed good reproducibility, selectivity and stability towards BPA. The sensor has been used to detect BPA in a different type of commercial plastic products as a real sample and satisfactory result was obtained when compared with the HPLC method. Conclusion: The proposed electrochemical laccase biosensor exhibits good result which is considered as a promising candidate for a simple, rapid and sensitive method especially in the resource- limited condition.

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Microwave-assisted synthesis of nitrogen doped carbon dots using prickly pear as the carbon source and its application as highly selective sensor for Cr(VI) and as patterning agent

Analytical Methods ◽

10.1039/d1ay01274f ◽

2021 ◽

Author(s):

Shreya Bhatt ◽

Gaurav Vyas ◽

Parimal Paul

Keyword(s):

Carbon Dots ◽

Microwave Assisted Synthesis ◽

Nitrogen Doped ◽

Water Dispersible ◽

Microwave Assisted ◽

Bio Imaging ◽

Natural Carbon ◽

Doped Carbon Dots ◽

Nitrogen Doped Carbon ◽

Selective Sensor

Preparation of water dispersible carbon dots from inexpensive natural carbon precursors and its application for purposes such as sensing, bio-imaging, patterning agent etc. is showing growing interest in recent years....

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