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Turcheniuk K.,Institut Universitaire de France | Hage C.-H.,Institut Universitaire de France | Spadavecchia J.,University Pierre and Marie Curie | Serrano A.Y.,SENSIA SL | And 8 more authors.
Journal of Materials Chemistry B | Year: 2015

The development of non-antibiotic based treatments against bacterial infections by Gram-negative uropathogenic E. coli is a complex task. New strategies to treat such infections are thus urgently needed. This report illustrates the development of pegylated reduced graphene oxide nanoparticles (rGO-PEG) and gold nanorods (Au NRs) coated with rGO-PEG (rGO-PEG-Au NRs) for the selective killing of uropathogenic E. coli UTI89. We took advantage of the excellent light absorption properties of rGO-PEG and Au NR particles in the near-infrared (NIR) region to photothermally kill Gram-negative pathogens up to 99% in 10 min by illumination of solutions containing the bacteria. The rGO-PEG-Au NRs demonstrated better photothermal efficiency towards E. coli than rGO-PEG. Targeted killing of E. coli UTI89 could be achieved with rGO-PEG-Au NRs functionalized with multimeric heptyl α-D-mannoside probes. This currently offers a unique biocompatible method for the ablation of pathogens with the opening of probably a new possibility for clinical treatments of patients with urinary infections. © The Royal Society of Chemistry 2015.

Zagorodko O.,Lille University of Science and Technology | Bouckaert J.,Lille University of Science and Technology | Dumych T.,Lille University of Science and Technology | Bilyy R.,Ukrainian Academy of Sciences | And 10 more authors.
Biosensors | Year: 2015

The colonization of Escherichia coli (E. coli) to host cell surfaces is known to be a glycan-specific process that can be modulated by shear stress. In this work we investigate whether flow rate changes in microchannels integrated on surface plasmon resonance (SPR) surfaces would allow for investigating such processes in an easy and high-throughput manner. We demonstrate that adhesion of uropathogenic E. coli UTI89 on heptyl α-D-mannopyranoside-modified gold SPR substrates is minimal under almost static conditions (flow rates of 10 μL·min-1), and reaches a maximum at flow rates of 30 μL·min-1 (≈30 mPa). This concept is applicable to the investigation of any ligand-pathogen interactions, offering a robust, easy, and fast method for screening adhesion characteristics of pathogens to ligand-modified interfaces. © 2015 by the authors.

Zagorodko O.,Lille University of Science and Technology | Spadavecchia J.,University Pierre and Marie Curie | Serrano A.Y.,SENSIA SL | Larroulet I.,SENSIA SL | And 4 more authors.
Analytical Chemistry | Year: 2014

Strategies employed to interface biomolecules with nanomaterials have considerably advanced in recent years and found practical applications in many different research fields. The construction of nucleic acid modified interfaces together with the label-free detection of hybridization events has been one of the major research focuses in science and technology. In this paper, we demonstrate the high interest of graphene-on-metal surface plasmon resonance (SPR) interfaces for the detection of DNA hybridization events in the attomolar concentration range. The strategy consists on the noncovalent functionalization of graphene-coated SPR interfaces with gold nanostars carrying single-stranded DNA (ssDNA). Upon hybridization with its complementary DNA, desorption of the nanostructures takes place and thus enables the sensitive detection of the DNA hybridization event. The DNA sensor exhibits a detection limit of ≈500 aM for complementary DNA with a linear dynamic range up to 10-8 M. This label-free DNA detection platform should spur off new interest toward the use of commercially available graphene-coated SPR interfaces. © 2014 American Chemical Society.

He L.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | He L.,Hebrew University of Jerusalem | Pagneux Q.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Larroulet I.,SENSIA SL | And 6 more authors.
Biosensors and Bioelectronics | Year: 2016

Sensitive and selective detection of cancer biomarkers is vital for the successful diagnosis of early stage cancer and follow-up treatment. Surface Plasmon Resonance (SPR) in combination with different amplification strategies is one of the analytical approaches allowing the screening of protein biomarkers in serum. Here we describe the development of a point-of-care sensor for the detection of folic acid protein (FAP) using graphene-based SPR chips. The exceptional properties of CVD graphene were exploited to construct a highly sensitive and selective SPR chip for folate biomarker sensing in serum. The specific recognition of FAP is based on the interaction between folic acid receptors integrated through π-stacking on the graphene coated SPR chip and the FAP analyte in serum. A simple post-adsorption of human serum:bovine serum albumin (HS:BSA) mixtures onto the folic acid modified sensor resulted in a highly anti-fouling interface, while keeping the sensing capabilities for folate biomarkers. This sensor allowed femtomolar (fM) detection of FAP, a detection limit well adapted and promising for quantitative clinical analysis. © 2016 Elsevier B.V.

Szunerits S.,Lille University of Science and Technology | Zagorodko O.,Lille University of Science and Technology | Cogez V.,French National Center for Scientific Research | Dumych T.,French National Center for Scientific Research | And 14 more authors.
Biology | Year: 2016

Shear force exerted on uropathogenic Escherichia coli adhering to surfaces makes type-1 fimbriae stretch out like springs to catch on to mannosidic receptors. This mechanism is initiated by a disruption of the quaternary interactions between the lectin and the pilin of the two-domain FimH adhesin and transduces allosterically to the mannose-binding pocket of FimH to increase its affinity. Mannose-specific adhesion of 14 E. coli pathovars was measured under flow, using surface plasmon resonance detection on functionalized graphene-coated gold interfaces. Increasing the shear had important differential consequences on bacterial adhesion. Adherent-invasive E. coli, isolated from the feces and biopsies of Crohn’s disease patients, consistently changed their adhesion behavior less under shear and displayed lower SPR signals, compared to E. coli opportunistically infecting the urinary tract, intestines or loci of knee and hip prostheses. We exemplified this further with the extreme behaviors of the reference strains UTI89 and LF82. Whereas their FimA major pilins have identical sequences, FimH of LF82 E. coli is marked by the Thr158Pro mutation. Positioned in the inter-domain region known to carry hot spots of mutations in E. coli pathotypes, residue 158 is indicated to play a structural role in the allosteric regulation of type-1 fimbriae-mediated bacterial adhesion. © 2016 by the authors; licensee MDPI, Basel, Switzerland.

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