scholarly journals A Nanocomposite Based on Reduced Graphene and Gold Nanoparticles for Highly Sensitive Electrochemical Detection of Pseudomonas aeruginosa through Its Virulence Factors

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1180 ◽  
Author(s):  
Islem Gandouzi ◽  
Mihaela Tertis ◽  
Andreea Cernat ◽  
Dalila Saidane-Mosbahi ◽  
Aranka Ilea ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gold Nanoparticles ◽  
Bacterial Infections ◽  
Electrochemical Sensors ◽  
Tap Water ◽  
Low Cost ◽  
Biological Contamination ◽  
Reduced Graphene ◽  
Highly Sensitive ◽  
Higher Sensitivity

Pyoverdine is a fluorescent siderophore produced by Pseudomonas aeruginosa that can be considered as a detectable marker in nosocomial infections. The presence of pyoverdine in water can be directly linked to the presence of the P. aeruginosa, thus being a nontoxic and low-cost marker for the detection of biological contamination. A novel platform was developed and applied for the electrochemical selective and sensitive detection of pyoverdine, based on a graphene/graphite-modified screen-printed electrode (SPE) that was electrochemically reduced and decorated with gold nanoparticles (NPs). The optimized sensor presenting higher sensitivity towards pyoverdine was successfully applied for its detection in real samples (serum, saliva, and tap water), in the presence of various interfering species. The excellent analytical performances underline the premises for an early diagnosis kit of bacterial infections based on electrochemical sensors.

scholarly journals Immobilization of Pseudomonas aeruginosa static biomass on eggshell powder for on-line preconcentration and determination of Cr (VI)

2020 ◽  
Vol 18 (1) ◽  
pp. 303-313 ◽  
Author(s):  
Aamir Rasheed ◽  
Tahseen Ghous ◽  
Sumaira Mumtaz ◽  
Muhammad Nadeem Zafar ◽  
Kalsoom Akhter ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Time Flow ◽  
Highly Sensitive ◽  
Glass Column ◽  
On Line ◽  
Preconcentration Time ◽  
Ultra Trace

AbstractIn the present work, a novel continuous flow system (CFS) is developed for the preconcentration and determination of Cr (VI) using Pseudomonas aeruginosa static biomass immobilized onto an effective and low-cost solid support of powdered eggshells. A mini glass column packed with the immobilized biosorbent is incorporated in a CFS for the preconcentration and determination of Cr (VI) from aqueous solutions. The method is based on preconcentration, washing and elution steps followed by colorimetric detection with 1,5-diphenyl carbazide in sulphuric acid. The effects of several variables such as pH, retention time, flow rate, eluent concentration and loaded volume are studied. Under optimal conditions, the CFS method has a linear range between 10 and 100 μg L-1 and a detection limit of 6.25 μg L-1 for the determination of Cr (VI). The sampling frequency is 10 samples per hour with a preconcentration time of 5 mins. Furthermore, after washing with a 0.1 M buffer (pH 3.0), the activity of the biosorbent is regenerated and remained comparable for more than 200 cycles. Scanning electron microscopy reveals a successful immobilization of biomass on eggshells powder and precipitation of Cr (VI) on the bacterial cell surface. The proposed method proves highly sensitive and could be suitable for the determination of Cr (VI) at an ultra-trace level.

Highly sensitive detection of hesperidin using AuNPs/rGO modified glassy carbon electrode

The Analyst ◽  
2018 ◽  
Vol 143 (1) ◽  
pp. 297-303 ◽  
Author(s):  
Yang Gao ◽  
Xiufeng Wu ◽  
Hui Wang ◽  
Wenbo Lu ◽  
Mandong Guo
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Reduced Graphene ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

The highly sensitive and selective electrochemical sensor of hesperidin based on gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) modified glassy carbon electrode (GCE) is reported.

Fabrication of Highly Sensitive and Selective Electrochemical Sensors for Detection of Paracetamol by Using Piroxicam Stabilized Gold Nanoparticles

2017 ◽  
Vol 164 (9) ◽  
pp. B427-B434 ◽  
Author(s):  
Syeda Sara Hassan ◽  
Sallahuddin Panhwar ◽  
Ayman Nafady ◽  
Abdullah M. Al-Enizi ◽  
Sirajuddin ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Electrochemical Sensors ◽  
Highly Sensitive

scholarly journals Rapid and highly sensitive detection of pyocyanin biomarker in different Pseudomonas aeruginosa infections using gold nanoparticles modified sensor

PLoS ONE ◽  
2019 ◽  
Vol 14 (7) ◽  
pp. e0216438 ◽  
Author(s):  
Amal A. Elkhawaga ◽  
Marwa M. Khalifa ◽  
Omnia El-badawy ◽  
Mona A. Hassan ◽  
Waleed A. El-Said
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gold Nanoparticles ◽  
Sensitive Detection ◽  
Highly Sensitive ◽  
Highly Sensitive Detection ◽  
Modified Sensor

scholarly journals A Highly Sensitive and Selective Colorimetric Hg2+ Ion Probe Using Gold Nanoparticles Functionalized with Polyethyleneimine

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Kyung Min Kim ◽  
Yun-Sik Nam ◽  
Yeonhee Lee ◽  
Kang-Bong Lee
Keyword(s):  
Gold Nanoparticles ◽  
Secondary Ion Mass Spectrometry ◽  
Color Change ◽  
Colorimetric Assay ◽  
Tap Water ◽  
Interparticle Distance ◽  
Pond Water ◽  
Assay Method ◽  
Tuna Fish ◽  
Highly Sensitive

A highly sensitive and selective colorimetric assay for the detection of Hg2+ ions was developed using gold nanoparticles (AuNPs) conjugated with polyethyleneimine (PEI). The Hg2+ ion coordinates with PEI, decreasing the interparticle distance and inducing aggregation. Time-of-flight secondary ion mass spectrometry showed that the Hg2+ ion was bound to the nitrogen atoms of the PEI in a bidentate manner (N–Hg2+–N), which resulted in a significant color change from light red to violet due to aggregation. Using this PEI-AuNP probe, determination of Hg2+ ion can be achieved by the naked eye and spectrophotometric methods. Pronounced color change of the PEI-AuNPs in the presence of Hg2+ was optimized at pH 7.0, 50°C, and 300 mM·NaCl concentration. The absorption intensity ratio (A700/A514) was correlated with the Hg2+ concentration in the linear range of 0.003–5.0 μM. The limits of detection were measured to be 1.72, 1.80, 2.00, and 1.95 nM for tap water, pond water, tuna fish, and bovine serum, respectively. Owing to its facile and sensitive nature, this assay method for Hg2+ ions can be applied to the analysis of water and biological samples.

scholarly journals Highly Sensitive and Selective Colorimetric Detection of Methylmercury Based on DNA Functionalized Gold Nanoparticles

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2679 ◽  
Author(s):  
Zheng-Jun Xie ◽  
Xian-Yu Bao ◽  
Chi-Fang Peng
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Limit Of Detection ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Colorimetric Method ◽  
Optimal Conditions ◽  
Surface Deposition ◽  
Highly Sensitive ◽  
Dna Strand

A new colorimetric detection of methylmercury (CH3Hg+) was developed, which was based on the surface deposition of Hg enhancing the catalytic activity of gold nanoparticles (AuNPs). The AuNPs were functionalized with a specific DNA strand (HT7) recognizing CH3Hg+, which was used to capture and separate CH3Hg+ by centrifugation. It was found that the CH3Hg+ reduction resulted in the deposition of Hg onto the surface of AuNPs. As a result, the catalytic activity of the AuNPs toward the chromogenic reaction of 3,3,5,5-tetramethylbenzidine (TMB)-H2O2 was remarkably enhanced. Under optimal conditions, a limit of detection of 5.0 nM was obtained for CH3Hg+ with a linear range of 10–200 nM. We demonstrated that the colorimetric method was fairly simple with a low cost and can be conveniently applied to CH3Hg+ detection in environmental samples.

scholarly journals Aptamer-based fluorescent detection of ochratoxin A by quenching of gold nanoparticles

RSC Advances ◽  
2017 ◽  
Vol 7 (27) ◽  
pp. 16290-16294 ◽  
Author(s):  
Xin Lv ◽  
Yuanfu Zhang ◽  
Guofu Liu ◽  
Lingyun Du ◽  
Shuhao Wang
Keyword(s):  
Gold Nanoparticles ◽  
Fluorescence Quenching ◽  
Ochratoxin A ◽  
Low Cost ◽  
Fluorescent Detection ◽  
Quenching Effect ◽  
Highly Sensitive ◽  
Sensitive Method

A simple, rapid, low cost and highly sensitive method for the detection of ochratoxin A (OTA) was developed based on the principle that dispersed AuNPs show a better fluorescence quenching effect than aggregated AuNPs.

scholarly journals Fluorescence and Naked-Eye Detection of Pb2+ in Drinking Water Using a Low-Cost Ionophore Based Sensing Scheme

2018 ◽  
Author(s):  
Aron Hakonen ◽  
Niklas Strömberg
Keyword(s):  
Drinking Water ◽  
Tap Water ◽  
Low Cost ◽  
Consumer Products ◽  
Lead Ion ◽  
Eye Detection ◽  
Naked Eye ◽  
Highly Sensitive ◽  
Naked Eye Detection

Drinking water contamination of lead from various environmental sources, leaching consumer products and intrinsic water-pipe infrastructure is still today a matter of great concern. Therefore, new highly sensitive and convenient Pb2+ measurement schemes are necessary, especially for in-situ measurements at a low-cost. Within this work dye/ionophore/Pb2+ co-extraction and effective water phase de-colorization was utilized for highly sensitive lead measurements and sub-ppb naked-eye detection. A low-cost ionophore Benzo-18-Crown-6-ether was used, and a simple test-tube mix and separate procedure was developed. Instrumental detection limits were in the low ppt region (LOD=3, LOQ=10), and naked-eye detection was 500 ppt. Note, however, that this sensing scheme still has improvement potential as concentrations of fluorophore and ionophore were not optimized. Artificial tap-water samples, leached by a standardized method, demonstrated drinking water application. Implications for this method are convenient in-situ lead ion measurements.

scholarly journals Simultaneous Detection of Dihydroxybenzene Isomers Using Electrochemically Reduced Graphene Oxide-Carboxylated Carbon Nanotubes/Gold Nanoparticles Nanocomposite

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 321
Author(s):  
Angélica Domínguez-Aragón ◽  
Rocio B. Dominguez ◽  
Erasto Armando Zaragoza-Contreras
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Tap Water ◽  
Simultaneous Detection ◽  
3D Network ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide ◽  
Carboxylated Carbon Nanotubes

An electrochemical sensor based on electrochemically reduced graphene oxide (ErGO), carboxylated carbon nanotubes (cMWCNT), and gold nanoparticles (AuNPs) (GCE/ErGO-cMWCNT/AuNPs) was developed for the simultaneous detection of dihidroxybenzen isomers (DHB) hydroquinone (HQ), catechol (CC), and resorcinol (RS) using differential pulse voltammetry (DPV). The fabrication and optimization of the system were evaluated with Raman Spectroscopy, SEM, cyclic voltammetry, and DPV. Under optimized conditions, the GCE/ErGO-cMWCNT/AuNPs sensor exhibited a linear concentration range of 1.2–170 μM for HQ and CC, and 2.4–400 μM for RS with a detection limit of 0.39 μM, 0.54 μM, and 0.61 μM, respectively. When evaluated in tap water and skin-lightening cream, DHB multianalyte detection showed an average recovery rate of 107.11% and 102.56%, respectively. The performance was attributed to the synergistic effects of the 3D network formed by the strong π–π stacking interaction between ErGO and cMWCNT, combined with the active catalytic sites of AuNPs. Additionally, the cMWCNT provided improved electrocatalytic properties associated with the carboxyl groups that facilitate the adsorption of the DHB and the greater amount of active edge planes. The proposed GCE/ErGO-cMWCNT/AuNPs sensor showed a great potential for the simultaneous, precise, and easy-to-handle detection of DHB in complex samples with high sensitivity.

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