@article {45632,
	title = {Reduced graphene oxide modified electrodes for sensitive sensing of gliadin in food samples},
	journal = {ACS Sensors},
	volume = {1},
	year = {2016},
	month = {DEC},
	pages = {1462-1470},
	type = {Article},
	abstract = {<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>},
	keywords = {anti-gliadin antibody, food samples, gliadin, Immunosensor, Porous reduced graphene oxide},
	issn = {2379-3694},
	doi = {10.1021/acssensors.6b00608},
	author = {Chekin, Fereshteh and Singh, Santosh K. and Vasilescu, Alina and Dhavale, Vishal M. and Kurungot, Sreekumar and Boukherroub, Rabah and Szunerits, Sabine}
}
@article {44129,
	title = { Porous reduced graphene oxide modified electrodes for the analysis of protein aggregation. part 1: lysozyme aggregation at pH 2 and 7.4},
	journal = {Electrochimica Acta},
	volume = {254},
	year = {2017},
	month = {NOV},
	pages = {375-383},
	type = {Article},
	abstract = {Protein instability due to misfolding and aggregation is of big concern for protein based therapeutics because it impacts the bioavailability and immunogenicity of such drugs. The development of simple and cost-effective methods for the analysis of pharmaceutical formulations, indicating the presence or absence of protein aggregates, is consequently of high importance. This work proposes a novel electrochemical interface based on porous reduced graphene oxide coated glassy carbon electrode (GC/prGO) allowing for the early and sensitive identification of protein aggregation by following the change in the oxidative current of the proteins. The novelty of this work lies in the exploration of the ability of GC/prGO interfaces to capture different aggregation behaviors. Lysozyme is used as a model to follow by electrochemistry its aggregation at two pH values, pH 2 and pH 7.4, leading to the formation of amyloid and amorphous aggregates, respectively. Comparing the oxidation peak of lysozyme by differential pulse voltammetry (DPV) for different electrode architectures allowed validating the higher sensitivity of the GC/prGO interface versus bare glassy electrodes or electrodes coated with non-porous reduced graphene oxide. Parallel experiments were performed by fluorescence with thioflavin T, size exclusion chromatography and Atomic Force Microscopy (AFM) imaging. These tests further highlighted the usefulness of GC/prGO electrode to visualize in a fast and reliable manner the changes in the protein structure and the differences between the processes occurring at pH 2 and pH 7.4. In particular, the ability to emphasize changes related to the first steps in aggregation that could be indicative of the aggregation course, recommend the GC/prGO electrode in combination with DPV as a new analytical tool for aggregation studies of biopharmaceuticals. Part 2 of this work will demonstrate later the utility of this approach for the analysis of a fast acting injectable human insulin formulation, Humulin R, used for diabetes treatment as well as for calcitonin. (C) 2017 Elsevier Ltd. All rights reserved.},
	doi = {10.1016/j.electacta.2017.09.083},
	author = {Vasilescu, Alina and Boulahneche, Samia and Chekin, Fereshteh and Gaspar, Szilveszter and Medjram, Mohamed Salah and Diagne, Abdou Aziz and Singh, Santosh K. and Kurungot, Sreekumar and Boukherroub, Rabah and Szunerits, Sabine}
}
@article {44552,
	title = {Porous reduced graphene oxide modified electrodes for the analysis of protein aggregation. Part 2: Application to the analysis of calcitonin containing pharmaceutical formulation},
	journal = {Electrochimica Acta},
	volume = {266},
	year = {2018},
	month = {MAR },
	pages = {364-372},
	abstract = {<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>},
	keywords = {Calcitonin, Disposable electrodes, Electrochemistry, Porous reduced graphene oxide, Protein aggregation},
	issn = {0013-4686},
	doi = {10.1016/j.electacta.2018.02.038},
	author = {Vasilescu, Alina and Ye, Ran and Boulahneche, Samia and Lamraoui, Sabrina and Jijie, Roxana and Medjram, Mohamed Salah and Gaspar, Szilveszter and Singh, Santosh K. and Kurungot, Sreekumar and Melinte, Sorin and Boukherroub, Rabah and Szunerits, Sabine}
}
@article {44362,
	title = {Sensitive electrochemical detection of cardiac troponin I in serum and saliva by nitrogen-doped porous reduced graphene oxide electrode},
	journal = {Sensors and Actuators B-Chemical},
	volume = {262},
	year = {2018},
	month = {JUN},
	pages = {180-187},
	type = {Article},
	abstract = {Cardiovascular diseases pose one of the highest mortality risks among all diseases in developed countries, steadily increasing the burden on the health systems. Early diagnosis of cardiovascular diseases has consequently become highly important to decrease mortality and to use more adapted therapeutic decisions. We demonstrate here the utility of nitrogen-doped reduced graphene oxide (N-prGO) for detecting and quantifying of cardiac troponin I (cTnI), a key human cardiac protein biomarker, under physiologically relevant conditions. Non-covalent modification of N-prGO by 1-pyrenecarboxylic acid (py-COOH) and poly(ethylene glycol) modified pyrene (py-PEG) ligands allowed the covalent integration of Tro4 aptamer, known for its high selectivity towards cTnI. Using differential pulse voltammetry (DPV), a label-free electrochemical sensor for cTnI for concentrations down to 1 pgmL(-1) in human serum could be obtained. This sensitive detection arises from the integration of a porous nanomaterial with excellent electrochemical properties being easily amendable to site-specific surface modification. (C) 2018 Elsevier B.V. All rights reserved.},
	doi = {10.1016/j.snb.2018.01.215},
	author = {Chekin, Fereshteh and Vasilescu, Alina and Jijie, Roxana and Singh, Santosh K. and Kurungot, Sreekumar and Iancu, Madalina and Badea, Gabriela and Boukherroub, Rabah and Szunerits, Sabine}
}
