Towards the Electrochemical Diagnostic of Influenza Virus: Development of Graphene-Au Hybrid Nanocomposite Modified Influenza Virus Biosensor Based on Neuraminidase Activity

International audienceAn effective electrochemical influenza A biosensor based on a graphene-gold (Au) hybrid nanocomposite modified Au-screen printed electrode has been developed. The working principle of the developed biosensor relies on the measurement of neuraminidase (N) activity. After the optimization of experimental parameters like the effect of bovine serum albumin addition and immobilization times of fetuin A and PNA lectin, the analytical characteristics of the influenza A biosensor were investigated. As a result, a linear range between 10-8 U mL-1 and 10-1 U mL-1 was found with a relative standard deviation value of 3.23% (for 10-5 U mL-1 of N, n:3) and a limit of detection value of 10-8 U mL-1 N. The developed biosensor was applied for real influenza virus A (H9N2) detection and very successful results were obtained

Graphene-metallic nanocomposites as modifiers in electrochemical glucose biosensor transducers

anik, ulku/0000-0002-3607-7208; Tepeli Buyuksunetci, Yudum/0000-0002-4717-7933WOS: 000397826400001Graphene sheets and three different graphene-metallic nanocomposites including graphene-copper (graphene-Cu), graphene-nickel (graphene-Ni) and graphene-platinum (graphene-Pt) were prepared and characterized in the first place. Then the electrochemical performances of these nanocomposites were tested in glucose biosensor transducers, which were formed by combining these metallic nanocomposites with glucose oxidase enzyme and glassy carbon paste electrode (GCPE). This is the first work that includes the usage of these graphene-Me nanocomposites as a part of glucose biosensor transducer. Fabricated amperometric biosensors linear ranges were obtained as follow: For the plain graphene, the linear range was found in the concentration range between 50 mu Mand 800 mu Mwith the RSD (n= 3 for 50 mu M glucose) value of 12.86% and LOD value of 7.2 mu M. For graphene-Pt modified glucose biosensor, the linear range was between 10 mu M and 600 mu M with the RSD (n= 3 for 50 mu M glucose) value of 3.45% and LOD value of 3.06 mu M. in the case of graphene-Ni modified glucose biosensor, the values were 25 mu M to 600 mu M with the RSD (n= 3 for 50 mu M glucose) value of 8.76% and LOD value of 24.71 mu M and for graphene-Cu modified glucose biosensor linear range was 25 mu M to 400 mu M with the RSD (n= 3 for 50 mu M glucose) value of 3.93% and LOD value of 2.87 mu M

An electrochemical cytosensor based on a PAMAM modified glassy carbon paste electrode

WOS: 000356801300099A novel electrochemical cytosensor was developed based on PAMAM and a folic acid (FA) modified glassy carbon paste electrode (GCPE) where HeLa cells were utilized as model cancer cells. For this purpose, gold nanoparticles (AuNp), cysteamin (Cys), glutaraldehyde (Glu), PAMAM and FA were immobilized onto the GCPE respectively. After the characterization of the GCPE/AuNp/Cys/Glu/PAMAM/FA cytosensor and optimization of the experimental parameters, analytical characteristics were examined. The linear range was found between 10(2) cells per mL and 10(6) cells per mL. The LOD value was calculated as 100 cells per mL with RSD value of 1.55% (for 5.0 x 10(4) HeLa cells per mL (n = 3)). The selectivity of the GCPE/AuNp/Cys/Glu/PAMAM/FA cytosensor was tested by using the folate negative cell line A549. The cytosensor's performance was also compared with similar previous studies. As a result, a selective, sensitive and practical system was developed

Application of Centri-voltammetry to Cytosensors: Cyto-centrivoltammetry

WOS: 000380904100009In this work, a centri-voltammetric cytosensor suitable for the for detection of folate receptor positive cervical cancer (HeLa) cells was developed for the first time. In order to see the effect of centrifugation, developed cytosensor's performance was compared in terms of analytical characteristics values, in the presence and absence of centri-voltammetry. As a result, in the absence of centri-voltammetry, the linear range was found between 75 cells/mL and 10(6) cells/mL with limit of detection (LOD) value as 75 cells/mL and with R.S.D value of 3.5% (for 5.0 x 10(4) HeLa cells/mL (n = 3)). Meanwhile in the presence of centri-voltammetry, the linear range was found between 8.0 cells/mL and 5 x 10(6) cells/mL and LOD value was calculated as 8 cells/mL with R.S.D value of 4.7% for the same concentration. (C) 2016 Elsevier Ltd. All rights reserved

Pseudomonas fragi/graphene-gold hybrid nanomaterial bioanode based microbial fuel cell

A Pseudomonas fragi (P. fragi) and graphene-gold hybrid nanomaterial included a carbon felt electrode (graphene-Au/CFE) bioanode was developed and optimized. Then, this bioanode was combined with a platinum cathode and a single cell compartment microbial fuel cell (MFC) was formed. To the best of our knowledge, this is the first study that has utilized P. fragi as a biocatalyst. After the optimization of the working parameters of P. fragi/graphene-Au/CFE bioanode, like the effect of benzoquinone (BQ) on bioanode performance, BQ concentration optimization, P. fragi bacteria amount and graphene-Au hybrid nanomaterial amount optimization, the characteristics of the developed MFC were examined. As a result, 0.169 V OCP, 23.80 mu A cm(-2) polarization and 0.50 mu W cm(-2) power density values together with remarkable lifetime (28 days) were obtained

Oxidase mimicking Co/2Fe MOF included biosensor for sialic acid detection

A facile amperometric biosensor that included oxidase mimicking Co/2Fe metal-organic framework (MOF) for sialic acid (SA) detection was prepared. Amperometric SA biosensor was constructed on a gold screen-printed electrode via immobilization of Co/2Fe MOF and N-acetylneuraminic Acid Aldolase (NANA-Aldolase) enzyme, respectively. NANA-Aldolase enzyme converts free SA into pyruvate and N-acetyl-D-mannosamine. After this conversion, oxidase mimicking Co/2Fe bimetallic MOF converts pyruvate into acetylphosphate and O2 into H2O2. Investigation of analytical characteristics resulted with the linear range of 0.02 mM-1.00 mM of SA concentration with limit of detection value of 0.026 mM. Sample application studies with developed SA biosensor were carried out with GD3 ganglioside and HeLa cancer cell lines which have high SA concentrations while A549 cell lines were also used as control group. Before detecting free SA, the bound SA was freed from SA sources where every step was monitored via electron impedance spectroscopy. Then, free SA was successfully detected with the amperometric SA biosensor and as a result, more practical and accurate system was developed.The grant from The Scientific and Technological Research Council of Turkey (TUBITAK) with Project No: 119R064 in the frame of COST Action (CA18103) was greatefully acknowledged.Scientific and Technological Research Council of Turkey (TUBITAK) [119R064, CA18103

Electrochemical detection of influenza virus H9N2 based on both immunomagnetic extraction and gold catalysis using an immobilization-free screen printed carbon microelectrode.

International audienceInfluenza is a viral infectious disease considered as a source of many health problems and enormous socioeconomic disruptions. Conventional methods are inadequate for in-field detection of the virus and generally suffer from being laborious and time-consuming. Thus, studies aiming to develop effective alternatives to conventional methods are urgently needed. In this work, we developed an approach for the isolation and detection of influenza A virus subtype H9N2. For this aim, two specific influenza receptors were used. The first, anti-matrix protein 2 (M2) antibody, was attached to iron magnetic nanoparticles (MNPs) and used for the isolation of the virus from allantoic fluid. The second biomolecule, Fetuin A, was attached to an electrochemical detectable label, gold nanoparticles (AuNPs), and used to detect the virus tacking advantage from fetuin-hemagglutinin interaction. The MNP-Influenza virus-AuNP formed complex was isolated and treated by an acid solution then the collected gold nanoparticles were deposited onto a screen printed carbon electrode. AuNPs catalyzes the hydrogen ions reduction in acidic medium while applying an appropriate potential, and the generated current signal was proportional to the virus titer. This approach allows the rapid detection of influenza virus A/H9N2 at a less than 16 HAU titer