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-samples02219nas a2200241   4500008004100000245011100041210006900152260000800221300001400229490000600243520137800249100002301627700001801650700002201668700002201690700002301712700002101735700002801756700002401784700002301808700002201831856012401853       2017                        eng d00aOn demand electrochemical release of drugs from porous reduced graphene oxide modified flexible electrodes0 ademand electrochemical release of drugs from porous reduced grap  cAUG  a6557-65650 v53 aDespite the advantages of an electrochemical control for drug release, only a handful of electrochemical-based release systems have been developed so far. We report herein on the development of an electrochemically activatable platform for on-demand delivery of drugs. It is based on flexible gold thin film electrodes coated with porous reduced graphene oxide (prGO) nanosheets onto which the drug of interest has been integrated beforehand. Two different drugs are investigated here: ondansetron hydrochloride (ODS), a selective 5-HT3 receptor antagonist used for preventing nausea and vomiting caused by chemotherapy and radiotherapy, and ampicillin (AMP), an antibiotic to prevent and treat a number of bacterial infections such as respiratory tract infections, urinary tract infections, and meningitis. In the case of ODS, application of a negative potential bias of -0.8 V results in a sustained slow ODS release with an ODS flux of 47 mu g cm(-2) h(-1). In the case of AMP, we show that polyethyleneimine modified prGO (prGO/PEI) is an extremely efficient matrix. Upon the application of +0.8 V, 24% of AMP could be released from the electrical interface in a time span of 2 h. The released AMP kept its antibacterial activity as demonstrated by antimicrobial tests. These examples illustrate the major benefits of the developed approach for biomedical applications.1 aBoulahneche, Samia1 aJijie, Roxana1 aBarras, Alexandre1 aChekin, Fereshteh1 aSingh, Santosh, K.1 aBouckaert, Julie1 aMedjram, Mohamed, Salah1 aKurungot, Sreekumar1 aBoukherroub, Rabah1 aSzunerits, Sabine  uhttps://library.ncl.res.in/content/demand-electrochemical-release-drugs-porous-reduced-graphene-oxide-modified-flexible03010nas a2200241   4500008004100000245014100041210006900182260000800251300001200259490000800271520213000279100002102409700002302430700002202453700002402475700002802499700002402527700002302551700002402574700002302598700002202621856012502643       2017                        eng d00a Porous reduced graphene oxide modified electrodes for the analysis of protein aggregation. part 1: lysozyme aggregation at pH 2 and 7.40 aPorous reduced graphene oxide modified electrodes for the analys  cNOV  a375-3830 v2543 aProtein 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.1 aVasilescu, Alina1 aBoulahneche, Samia1 aChekin, Fereshteh1 aGaspar, Szilveszter1 aMedjram, Mohamed, Salah1 aDiagne, Abdou, Aziz1 aSingh, Santosh, K.1 aKurungot, Sreekumar1 aBoukherroub, Rabah1 aSzunerits, Sabine  uhttps://library.ncl.res.in/content/porous-reduced-graphene-oxide-modified-electrodes-analysis-protein-aggregation-part-102139nas a2200217   4500008004100000245014400041210006900185260000800254300001300262490000800275520132900283100002201612700001701634700002901651700001801680700002301698700002401721700002301745700002201768856013101790       2018                        eng d00aNucleic aptamer modified porous reduced graphene oxide/MoS2 based electrodes for viral detection: application to human papillomavirus (HPV)0 aNucleic aptamer modified porous reduced graphene oxideMoS2 based  cJUN  a991-10000 v2623 aNext to graphene nanomaterials, molybdenum disulfide (MoS2) offers large surface area that can enhance its biosensing performance. In this work, we investigate the performance of glassy carbon (GC) electrodes modified successively with porous reduced graphene oxide (prGO) and molybdenum sulfide (MoS2) for the sensitive and selective detection of the L1-major capsid protein of human papilloma virus (HPV). Owing to the difficulties to perform serological assays and HPV culture efficiently, tools based on molecular recognition are becoming of great importance. We developed here an electrochemical sensor for HPV upon covalent functionalization of the electrode with an aptamer Sc5-c3, a RNA aptamer targeted against the HPV-16 L1 protein. Using differential pulse voltammetry (DPV) and an optimized sensor interface, a linear relationship between the peak current density of a redox couple such as [Fe(CN)6]4- and the concentration of HPV-16 L1 proteins in the range of 0.2-2 ng mL(-1) (3.5 pM-35.3 pM) could be reached with a detection limit of 0.1 ng mL(-1) (1.75 pM). Cross-reactivity studies demonstrated high selectivity over potential interfering species such as HPV-16 E6, opening new opportunities of the developed concept for the development of point of care devices. (C) 2018 Elsevier B.V. All rights reserved.1 aChekin, Fereshteh1 aBagga, Komal1 aSubramanian, Palaniappan1 aJijie, Roxana1 aSingh, Santosh, K.1 aKurungot, Sreekumar1 aBoukherroub, Rabah1 aSzunerits, Sabine  uhttps://library.ncl.res.in/content/nucleic-aptamer-modified-porous-reduced-graphene-oxidemos2-based-electrodes-viral-detection01983nas a2200229   4500008004100000245014000041210006900181260000800250300001200258490000800270520115600278100002201434700002101456700001801477700002301495700002401518700002001542700002001562700002301582700002201605856012601627       2018                        eng d00aSensitive electrochemical detection of cardiac troponin I in serum and saliva by nitrogen-doped porous reduced graphene oxide electrode0 aSensitive electrochemical detection of cardiac troponin I in ser  cJUN  a180-1870 v2623 aCardiovascular 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.1 aChekin, Fereshteh1 aVasilescu, Alina1 aJijie, Roxana1 aSingh, Santosh, K.1 aKurungot, Sreekumar1 aIancu, Madalina1 aBadea, Gabriela1 aBoukherroub, Rabah1 aSzunerits, Sabine  uhttps://library.ncl.res.in/content/sensitive-electrochemical-detection-cardiac-troponin-i-serum-and-saliva-nitrogen-doped01952nas a2200277   4500008004100000022001400041245008700055210006900142260000800211300001400219490000800233520105700241653002601298653001601324653004201340653001001382100002201392700002201414700001201436700001901448700002301467700002401490700002301514700002201537856011501559       2019                        eng d  a1618-264200aGraphene-modified electrodes for sensing doxorubicin hydrochloride in human plasma0 aGraphenemodified electrodes for sensing doxorubicin hydrochlorid  cMAR  a1509-15160 v4113 a<p>Doxorubicin (DOX), an anthracycline molecule, is currently one of the most widely used anticancer drugs in clinics. Systematic treatment of patients with DOX is known to be accompanied by several unpleasant side effects due to the toxicity of the drug. Thus, monitoring of DOX concentration in serum samples has become increasingly important to avoid side effects and ensure therapeutic efficiency. In this study, we discuss the construction of a disposable electrochemical sensor for the direct monitoring of DOX in clinical blood samples. The sensor is based on coating a gold electrode in a flexible integrated electrode construct formed on polyimide sheets using photolithography, with nitrogen-doped reduced graphene oxide (N-rGO) suspended in chitosan. Under optimized conditions, a linear relationship between the oxidative peak current and the concentration of DOX in the range of 0.010-15M with a detection limit of 10nM could be achieved. The sensor was adapted to monitor DOX in serum samples of patients under anticancer treatment.</p>
10aDisposable electrodes10adoxorubicin10aNitrogen-doped reduced graphene oxide10aSerum1 aChekin, Fereshteh1 aMyshin, Vladyslav1 aYe, Ran1 aMelinte, Sorin1 aSingh, Santosh, K.1 aKurungot, Sreekumar1 aBoukherroub, Rabah1 aSzunerits, Sabine  uhttps://library.ncl.res.in/content/graphene-modified-electrodes-sensing-doxorubicin-hydrochloride-human-plasma