scholarly journals Development of Flexible Dispense-Printed Electrochemical Immunosensor for Aflatoxin M1 Detection in Milk

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3912 ◽  
Author(s):  
Biresaw Demelash Abera ◽  
Aniello Falco ◽  
Pietro Ibba ◽  
Giuseppe Cantarella ◽  
Luisa Petti ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Electrochemical Immunosensor ◽  
Aflatoxin M1 ◽  
Quality And Safety ◽  
Buffer Solution ◽  
Detection Range ◽  
Fabrication Cost ◽  
Food Quality And Safety ◽  
Walled Carbon Nanotubes

Detection of mycotoxins, especially aflatoxin M1 (AFM1), in milk is crucial to be able to guarantee food quality and safety. In recent years, biosensors have been emerging as a fast, reliable and low-cost technique for the detection of this toxin. In this work, flexible biosensors were fabricated using dispense-printed electrodes, which were functionalized with single-walled carbon nanotubes (SWCNTs) and subsequently coated with specific antibodies to improve their sensitivity. Next, the immunosensor was tested for the detection of AFM1 in buffer solution and a spiked milk sample using a chronoamperometric technique. Results showed that the working range of the sensors was 0.01 µg/L at minimum and 1 µg/L at maximum in both buffer and spiked milk. The lower limit of detection of the SWCNT-functionalized sensor was 0.02 µg/L, which indicates an improved sensitivity compared to the sensors reported so far. The sensitivity and detection range were in accordance with the limitation values imposed by regulations on milk and its products. Therefore, considering the low fabrication cost, the ease of operation, and the rapid read-out, the use of this sensor could contribute to safeguarding consumers’ health.

scholarly journals D-shaped plastic optical fibre aptasensor for fast thrombin detection in nanomolar range

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nunzio Cennamo ◽  
Laura Pasquardini ◽  
Francesco Arcadio ◽  
Lia E. Vanzetti ◽  
Alessandra Maria Bossi ◽  
...  
Keyword(s):  
Optical Fibre ◽  
Photoelectron Spectroscopy ◽  
Limit Of Detection ◽  
Low Cost ◽  
Gold Surface ◽  
Coagulation Cascade ◽  
Self Assembled Monolayer ◽  
Detection Range ◽  
Clinical Biomarkers ◽  
Static Contact

AbstractThe development of optical biosensors for the rapid and costless determination of clinical biomarkers is of paramount importance in medicine. Here we report a fast and low-cost biosensor based on a plasmonic D-shaped plastic optical fibre (POF) sensor derivatized with an aptamer specific for the recognition of thrombin, the target marker of blood homeostasis and coagulation cascade. In particular, we designed a functional interface based on a Self Assembled Monolayer (SAM) composed of short Poly Ethylene Glycol (PEG) chains and biotin-modified PEG thiol in ratio 8:2 mol:mol, these latter serving as baits for the binding of the aptamer through streptavidin-chemistry. The SAM was studied by X-ray Photoelectron Spectroscopy (XPS) analysis, static contact angle (CA), Surface Plasmon Resonance (SPR) in POFs, and fluorescence microscopy on gold surface. The optimized SAM composition enabled the immobilization of about 112 ng/cm2 of aptamer. The thrombin detection exploiting POF-Aptasensor occurred in short times (5–10 minutes), the reached Limit of Detection (LOD) was about 1 nM, and the detection range was 1.6–60 nM, indicating the POF-Aptasensor well addresses the needs for a low-cost, simple to use and to realize, rapid, small size and portable diagnostic platform.

scholarly journals An Electrochemical Immunosensor Based on SPA and rGO-PEI-Ag-Nf for the Detection of Arsanilic Acid

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 172
Author(s):  
Yanwei Wang ◽  
Dongdong Ma ◽  
Gaiping Zhang ◽  
Xuannian Wang ◽  
Jingming Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Limit Of Detection ◽  
Electrochemical Immunosensor ◽  
Detection Range ◽  
Optimal Experiment ◽  
Arsanilic Acid ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Good Potential ◽  
The Stability

A sensitive electrochemical immunosensor was prepared for rapid detection of ASA based on arsanilic acid (ASA) monoclonal antibody with high affinity. In the preparation of nanomaterials, polyethyleneimine (PEI) improved the stability of the solution and acted as a reducing agent to generate reduced graphene oxide (rGO) with relatively strong conductivity, thereby promoting the transfer of electrons. The dual conductivity of rGO and silver nanoparticles (AgNPs) improved the sensitivity of the sensor. The synthesis of nanomaterials were confirmed by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy and scanning electron microscopy. In the optimal experiment conditions, the sensor could achieve the detection range of 0.50–500 ng mL−1 and the limit of detection (LOD) of 0.38 ng mL−1 (S/N = 3). Moreover, the sensor exhibited excellent specificity and acceptable stability, suggesting that the proposed sensor possessed a good potential in ASA detection. Thus, the as-prepared biosensor may be a potential way for detecting other antibiotics in meat and animal-derived foods.

scholarly journals An Impedance Based Electrochemical Immunosensor for Aflatoxin B1 Monitoring in Pistachio Matrices

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 121
Author(s):  
Michail D. Kaminiaris ◽  
Sophie Mavrikou ◽  
Maria Georgiadou ◽  
Georgia Paivana ◽  
Dimitrios I. Tsitsigiannis ◽  
...  
Keyword(s):  
Aflatoxin B1 ◽  
Limit Of Detection ◽  
Electrochemical Immunosensor ◽  
Aflatoxin M1 ◽  
Biomolecular Recognition ◽  
Effective Prevention ◽  
Upper Limits ◽  
Ethylcarbodiimide Hydrochloride ◽  
Food And Feed

Aflatoxins are highly toxic fungal secondary metabolites that often contaminate food and feed commodities. An electrochemical immunosensor for the determination of aflatoxin B1 (AFB1) was fabricated by immobilizing monoclonal AFB1 antibodies onto a screen-printed gold electrode that was modified with carbo-methyldextran by N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide cross-linking. An electrochemical interfacial modelling of biomolecular recognition was suggested and reasonably interpreted. Impedance technology was employed for the quantitative determination of AFB1. The limit of detection concentration of AFB1 for standard solutions and spiked pistachio samples was 0.5 ng/mL and 1 ng/mL, respectively. The immunosensor was able to successfully determine AFB1 concentrations in the range of 4.56–50.86 ng/mL in unknown pistachio samples. Comparative chromatographic analysis revealed that AFB1 concentrations that were higher than 345 ng/mL were not within the immunosensor’s upper limits of detection. Selectivity studies against Ochratoxin A and Aflatoxin M1 demonstrated that the proposed AFB1 immunosensor was able to differentiate between these other fungal mycotoxins. The novel electrochemical immunosensor approach has the potential for rapid sample screening in a portable, disposable format, thus contributing to the requirement for effective prevention and the control of aflatoxin B1 in pistachios.

scholarly journals Direct immunosensing of avian influenza A virus in whole blood using hybrid nanocomposites

2018 ◽  
Author(s):  
John Buozis ◽  
Syed Rahin Ahmed ◽  
Rohit Chand ◽  
Éva Nagy ◽  
Suresh Neethirajan
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Hybrid Nanocomposites ◽  
Buffer Solution ◽  
Solution Ph ◽  
Detection Range ◽  
Viral Antibodies ◽  
Elisa Testing

AbstractA sandwich-based electrochemical immunosensor was designed for detection of avian influenza virus (AIV) strains H5N1 and H4N6. This sensor was developed using gold-graphene nanocomposites, immobilized viral antibodies, and CdTe quantum dot electrochemical tagging. The nanocomposites were formed by the simultaneous reduction of a gold salt and graphene using hydroquinone as the reducing agent, thus producing non-spherical gold nanoparticles on graphene sheets. Viral antibodies were immobilized on nanocomposites and CdTe quantum dots through N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide and N-hydroxysuccinimide chemistry. Cyclic voltammetry studies were used to validate the detection of H5N1 surface protein and H4N6 inactivated virus. The immunosensor detected H5 protein in phosphate buffer solution (pH 7.4) with a limit of detection (LOD) of 10 fg/mL and a linear detection range was established for 10 ng/mL to 10 pg/mL. The biosensor detected H4N6 in three parts diluted whole chicken blood with a LOD of 1.28×10−7 hemagglutinating units (HAU). Commercial ELISA testing for H5N1 and H4N6 showed limits of detection of 10 ng/mL and 0.128 HAU, respectively. The sensor showed 106-fold increased detection of H4N6 virus in blood in comparison to its commercial ELISA kit counterpart. The developed immunosensor effectively change the way avian influenza is detected, monitored, and controlled; transforming time-consuming reactive methods, into rapid predictive technology.

scholarly journals Dendrites Nanostructures of Co3O4 for the Selective Determination of Uric Acid

2021 ◽  
Author(s):  
Ramesh Lal ◽  
Bhajan Lal Bhattia ◽  
Ali M. Alsalme ◽  
Asma A. Al-Othman ◽  
Ayman Nafady ◽  
...  
Keyword(s):  
Composite Material ◽  
Uric Acid ◽  
Limit Of Detection ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Clinical Samples ◽  
Buffer Solution ◽  
Solution Ph ◽  
Dendrite Morphology ◽  
Selective Determination

Abstract The gout is mainly found due to accumulation of uric acid crystals into the joints which produces the inflammatory symptoms. Thus, it is highly demanded to detect uric acid from our body. Herein, we used wet chemical method for the preparation of composite material of cobalt oxide (Co3O4) with hydroxide functionalized multi-walled carbon nanotubes (MWCNTs). The analytical techniques such as scanning electron microscopy (SEM), powder X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and Infra-red spectroscopy (FTIR) were used to characterize the composite material. The Co3O4 exhibits a dendrite morphology and very well chemically coupled with MWCNTs. The elemental analysis confirmed the presence of Co, O and C as main constituent of the composite material. The Co3O4 exhibits a cubic unit cell crystallography in the composite system. The FTIR study has revealed the characteristic bands of Co-O bands in the composite material. The cyclic voltammetry was used to study the electrochemical properties of prepared materials. The composite sample with highest percentage of MWCNTs showed an excellent electrochemical activity towards the oxidation of uric acid in phosphate buffer solution pH 7.3. The enzyme free uric acid sensor possessed a linear range of 0.1 mM to 3 mM with a quantified limit of detection of 0.005 mM. The modified electrode is stable, selective, and very sensitive towards uric acid, therefore it may be used for the monitoring of uric acid from clinical samples. The proposed composite material is low cost, and earth abundant, thus it can be of great interest for energy and biomedical fields.

Enforcing Food Quality and Safety Standards in Brazil

2013 ◽  
Vol 649 (1) ◽  
pp. 122-138 ◽  
Author(s):  
Salo Coslovsky
Keyword(s):  
Product Quality ◽  
Police Officers ◽  
Low Cost ◽  
Business Environment ◽  
Quality And Safety ◽  
Product Lines ◽  
Safety Standards ◽  
Top Executives ◽  
Food And Beverage ◽  
Food Quality And Safety

In numerous product lines, globalization of production has been accompanied by increasingly austere product quality and safety regulations. These regulations are particularly stringent in the food and beverage sectors and put enormous strain on producers from developing nations. This article examines a cooperative of sugarcane, sugar, and ethanol producers from Brazil that, when confronted with the challenge of new regulations, adopted three policies that encouraged its members to upgrade quality and safety standards, enabling them to compete successfully in a demanding business environment. I argue that the co-op’s success was due to (1) a new cost accounting methodology that monetized some of the differences in product quality, attenuating tensions among members; (2) a low-cost, high-powered system of regulatory incentives that empowered middle managers vis-à-vis top executives within regulated firms; and (3) external auditors who acted not as police officers or consultants but as conduits, reestablishing information flows and helping to create a business atmosphere conducive to productive change.

scholarly journals Flexible and Printed Electrochemical Immunosensor Coated with Oxygen Plasma Treated SWCNTs for Histamine Detection

Biosensors ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 35 ◽  
Author(s):  
Bajramshahe Shkodra ◽  
Biresaw Demelash Abera ◽  
Giuseppe Cantarella ◽  
Ali Douaki ◽  
Enrico Avancini ◽  
...  
Keyword(s):  
Oxygen Plasma ◽  
Electrochemical Immunosensor ◽  
Coefficient Of Determination ◽  
Time Stability ◽  
Detection Range ◽  
Relative Response ◽  
Linear Detection ◽  
Fish Samples ◽  
Amino Acid Histidine ◽  
Walled Carbon Nanotubes

Heterocyclic amine histamine is a well-known foodborne toxicant (mostly linked to “scombroid poisoning”) synthesized from the microbial decarboxylation of amino acid histidine. In this work, we report the fabrication of a flexible screen-printed immunosensor based on a silver electrode coated with single-walled carbon nanotubes (SWCNTs) for the detection of histamine directly in fish samples. Biosensors were realized by first spray depositing SWCNTs on the working electrodes and by subsequently treating them with oxygen plasma to reduce the unwanted effects related to their hydrophobicity. Next, anti-histamine antibodies were directly immobilized on the treated SWCNTs. Histamine was detected using the typical reaction of histamine and histamine-labeled with horseradish peroxidase (HRP) competing to bind with anti-histamine antibodies. The developed immunosensor shows a wide linear detection range from 0.005 to 50 ng/mL for histamine samples, with a coefficient of determination as high as 98.05%. Average recoveries in fish samples were observed from 96.00% to 104.7%. The biosensor also shows good selectivity (less than 3% relative response for cadaverine, putrescine, and tyramine), reproducibility, mechanical and time stability, being a promising analytical tool for the analysis of histamine, as well as of other food hazards.

Recent Developments in Electrochemical Determination of Sulfonamides

2020 ◽  
Vol 17 ◽  
Author(s):  
Li Fu ◽  
Xinyi Zhang ◽  
Su Ding ◽  
Fei Chen ◽  
Yanfei Lv ◽  
...  
Keyword(s):  
Human Health ◽  
Limit Of Detection ◽  
Low Cost ◽  
High Sensitivity ◽  
Cost Effective ◽  
Electrochemical Determination ◽  
Veterinary Antibiotics ◽  
Drug Residues ◽  
Detection Range

Background: Sulfonamides are the anti-bacterial and anti-inflammatory drugs synthesized, which are widely used as medical and veterinary antibiotics. However, the excess dosage of sulfonamides can harm human health. The drug residues in the animal products also can harm human health through the food chain. The long-term consumption of animal food containing drug residues will cause some toxic and side effects on human body functions, which will seriously threaten human health. Methods: Electroanalytical methods are attracting much attention because of their advantage over conventional methods, as they are quick, low-cost, high sensitivity, and portable. This review examines the progress made in the selective electrochemical determination of sulfonamides in the last 20 years. Results: In this review, we describe the development of electrochemical methods for sulfonamides determination. Then, we pay special attention to the detection of sulfonamides using molecular imprinting technology. The linear detection range with the limit of detection has been listed for comparison. Conclusion: Electrochemical determination of sulfonamides is a fast, simple, sensitive, and cost-effective approach. The surface modification of commercial electrodes can significantly improve the sensing performance.

scholarly journals A Label-Free Fluorescent AND Logic Gate Aptasensor for Sensitive ATP Detection

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3281 ◽  
Author(s):  
Jingjing Zhang ◽  
Chunzheng Yang ◽  
Chaoqun Niu ◽  
Chen Liu ◽  
Xuepin Cai ◽  
...  
Keyword(s):  
Deoxyribonucleic Acid ◽  
Limit Of Detection ◽  
Low Cost ◽  
Logic Gate ◽  
Label Free ◽  
Detection Range ◽  
Sensitivity Range ◽  
Highly Sensitive ◽  
Input Signals ◽  
Atp Detection

In this study, a label-free fluorescent, enzyme-free, simple, highly sensitive AND logic gate aptasensor was developed for the detection of adenosine triphosphate (ATP). Double-stranded deoxyribonucleic acid (DNA) with cohesive ends was attached to graphene oxide (GO) to form an aptasensor probe. ATP and single-stranded DNA were used as input signals. Fluorescence intensity of PicoGreen dye was used as an output signal. The biosensor-related performances, including the logic gate construction, reaction time, linearity, sensitivity, and specificity, were investigated and the results showed that an AND logic gate was successfully constructed. The ATP detection range was found to be 20 to 400 nM (R2 = 0.9943) with limit of detection (LOD) of 142.6 pM, and the sensitivity range was 1.846 × 106 to 2.988 × 106 M−1. This method for the detection of ATP has the characteristics of being simple, low cost, and highly sensitive.

scholarly journals Ta2O5/rGO Nanocomposite Modified Electrodes for Detection of Tryptophan through Electrochemical Route

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 811 ◽  
Author(s):  
Shun Zhou ◽  
Zefeng Deng ◽  
Zhongkang Wu ◽  
Mei Xie ◽  
Yaling Tian ◽  
...  
Keyword(s):  
Human Serum ◽  
Limit Of Detection ◽  
Human Life ◽  
Phosphate Buffer Solution ◽  
Modified Electrodes ◽  
Essential Amino Acids ◽  
Buffer Solution ◽  
Solution Ph ◽  
Catalytic Systems ◽  
Detection Range

l-tryptophan is one of the eight kinds of essential amino acids for sustainable human life activity. It is common to detect the concentration of tryptophan in human serum for diagnosing and preventing brain related diseases. Herein, in this study, GCE (glassy carbon electrode) modified by Ta2O5-reduced graphene oxide (-rGO) composite (Ta2O5-rGO-GCE) is synthesized by the hydrothermal synthesis-calcination methods, which is used for detecting the concentration of tryptophan in human serum under the as-obtained optimal detection conditions. As a result, the obtained Ta2O5-rGO-GCE shows larger electrochemical activity area than other bare GCE and rGO-GCE due to the synergistic effect of Ta2O5 NPs and rGO. Meanwhile, Ta2O5-rGO-GCE shows an excellent response to tryptophan during the oxidation process in 0.1 M phosphate buffer solution (pH = 6). Moreover, three wide linear detection range (1.0–8.0 μM, 8.0–80 μM and 80–800 μM) and a low limit of detection (LOD) of 0.84 μM (S/N = 3) in the detection of tryptophan are also presented, showing the larger linear ranges and lower detection limit by employing Ta2O5-rGO-GCE. Finally, the as-proposed Ta2O5-rGO-GCE with satisfactory recoveries (101~106%) is successfully realized for the detection of tryptophan in human serum. The synthesis of Ta2O5-rGO-GCE in this article could provide a slight view for the synthesis of other electrochemical catalytic systems in detection of trace substance in human serum.

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