02222nas a2200277   4500008004100000022001400041245009600055210006900151260000800220300001400228490000600242520131000248653002601558653001701584653001201601653001701613653003401630100002201664700002301686700002101709700002401730700002401754700002301778700002201801856012101823       2016                        eng d  a2379-369400aReduced graphene oxide modified electrodes for sensitive sensing of gliadin in food samples0 aReduced graphene oxide modified electrodes for sensitive sensing  cDEC  a1462-14700 v13 a<p>Incidences of food allergies are on the rise, which can greatly affect the well-being of children as well as adults. Intolerance to gluten, a protein composite of gliadin and glutenin, present in wheat, barley, and rye and several cereals, can be the causative agent of celiac disease (CD) and other allergic reactions. A gluten-free diet has become essential for people affected by CD, and consequently, the amount of gluten in food products needs to be strictly controlled. In this paper, we report an electrochemical label-free immunosensor for ultrasensitive and specific detection of gliadin. The sensor takes advantage of the specific properties of porous reduced graphene oxide (prGO) covalently functionalized with anti-gliadin antibodies using 1-pyrenecarboxylic acid as linker molecule. Using differential pulse voltammetry (DPV) and [Fe(CN)6](3-/4-) as a redox probe, a decrease of current is linked to the presence of gliadin. The sensor achieved a detection limit of 1.2 ng mL(-1) over a 1.2-34 ng mL(-1) linear range with high selectivity. The advantages offered by this sensor are the possibility to regenerate the surface of the immunosensor, its rapid and ease of production, as well as applicability for the screening of gliadin concentrations in real food samples, as shown here.</p>10aanti-gliadin antibody10afood samples10agliadin10aImmunosensor10aPorous reduced graphene oxide1 aChekin, Fereshteh1 aSingh, Santosh, K.1 aVasilescu, Alina1 aDhavale, Vishal, M.1 aKurungot, Sreekumar1 aBoukherroub, Rabah1 aSzunerits, Sabine  uhttps://library.ncl.res.in/content/reduced-graphene-oxide-modified-electrodes-sensitive-sensing-gliadin-food-samples02837nas a2200337   4500008004100000022001400041245018300055210006900238260000900307300001200316490000800328520165900336653001501995653002602010653002102036653003402057653002402091100002102115700001202136700002302148700002202171700001802193700002802211700002402239700002302263700002402286700001902310700002302329700002202352856012502374       2018                        eng d  a0013-468600aPorous reduced graphene oxide modified electrodes for the analysis of protein aggregation. Part 2: Application to the analysis of calcitonin containing pharmaceutical formulation0 aPorous reduced graphene oxide modified electrodes for the analys  cMAR   a364-3720 v2663 a<p>In part 1 (A. Vasilescu et al., Porous reduced graphene oxide modified electrodes for the analysis of protein aggregation. Part 1: Lysozyme aggregation at pH 2 and 7.4 Electrochem. Acta, 254 (2017) 375 -383) we proposed porous reduced graphene oxide coated glassy carbon electrode (GC/prGO) in combination with differential pulse voltammetry as a new analytical tool for aggregation studies of proteins. Lysozyme was used as a model to follow its aggregation by electrochemical means at pH 2 and pH 7.4, leading to the formation of amyloid and amorphous aggregates, respectively. Part 2 of this work widens the scope of this approach by investigating a biopharmaceutical product, as the aggregation of peptide based drugs affects their therapeutic activity and can induce allergic reactions in patients. The salmon polypeptide calcitonin (sCT) was chosen as an example of a bioactive peptide with limited pharmaceutical potential due to a tendency to form cytotoxic aggregates and amyloid fibrils. For practical applications, screen printed electrodes (SPE) and flexible electrodes (FE) modified with polydiallyldimethylammonium (PDDA) and prGO by using the layer-by-layer deposition technique have been developed for the detection of sCT. The results indicate that these electrodes can differentiate between formation of amyloid aggregates of calcitonin (2 mg mL(-1)) in citrate buffer to no aggregation in acetate buffer. It was further demonstrated that these electrodes are able to analyze a pharmaceutical drug product of low potency, Miacalcic (8.3 mu g mL(-1)), where no aggregation was observed. (C) 2018 Elsevier Ltd. All rights reserved.</p>10aCalcitonin10aDisposable electrodes10aElectrochemistry10aPorous reduced graphene oxide10aProtein aggregation1 aVasilescu, Alina1 aYe, Ran1 aBoulahneche, Samia1 aLamraoui, Sabrina1 aJijie, Roxana1 aMedjram, Mohamed, Salah1 aGaspar, Szilveszter1 aSingh, Santosh, K.1 aKurungot, Sreekumar1 aMelinte, Sorin1 aBoukherroub, Rabah1 aSzunerits, Sabine  uhttps://library.ncl.res.in/content/porous-reduced-graphene-oxide-modified-electrodes-analysis-protein-aggregation-part-2