Existing electrochemical sensors for environmental monitoring suffer from limitations in terms of sensitivity and selectivity. Better sensors are needed to respond to the rising societal demand for continuous information on environmental safety. The HYPERION project will investigate the development of functionalised membranes hierarchically porous to form a new class of electrochemical sensors based on ion transfer voltammetry. The sensors will consist of a macroporous polymeric membrane modified electrochemically with a mesoporous silica film. This project will focus on (i) the preparation of hierarchically porous membranes using sol-gel chemistry and micro-fabrication methods, (ii) the understanding of the formation mechanism and (iii) the exploitation of the selectivity properties of the pore dimension and of the surface chemistry for analytical applications. The research developed in this project will combine (i) microscopic features to improve the mass transport and (ii) mesopores with chemical functions to boost both sensibility and selectivity. This project will establish the fundamental knowledge for the development of a novel class of electrochemical sensors.

Adhesion of micro-organisms, in particular bacteria, plays an important role in biofilms formation and the colonization of biotic or abiotic surfaces. These biofilms can be formed on any type of surfaces, and represent important financial losses e.g. in food and water treatment industries. Moreover, biofilms can constitute a major risk to public health (hospital environment, agro-industry). Bacterial cells forming the biofilms can indeed show higher resistance to bactericides, biocides and other antibiotic molecules as compared to that shown by planktonic bacteria. In the past decade, many strategies were developed to prevent biofilms formation. For instance, some of them consisted in chemically modifying surfaces by grafting antimicrobial molecules or by depositing an anti-adhesive layer. However, these strategies are generally not very satisfactory in terms of cost, environmental impact, toxicity and effectiveness in time. The project proposed here aims to design a new type of antibacterial coating to prevent biofilms formation at mid-term. The originality of our project lies in the choice to immobilize and store bacteriophages into a biomaterial matrix and to use viral infection processes as a basis for preventing biofilm formation. This may allow for the adhesion of other cells or bacteria onto the support. The selected coating/biomaterial is a polyelectrolyte multilayer film (PEM) able to trap, store and possibly release phages. In addition, it is expected that the chosen coating will be able to self-regenerate in terms of functionalization by reincorporating the phages released after bacterial lysis. Since the end of the 90’s, studies performed on biomaterials, in particular (PEM) films, highlighted that these new materials have innovating and flexible properties (viscoelasticity, hydrophobicity, hydration, tank effect) and a large range of potential applications in various fields (biomedicine, agrobusiness, aircraft, pharmaceutical industries). In addition, PEMs are not expensive, easy to manufacture and do not show environmental impact or toxicity. Infection mechanisms of bacteria by phages are a natural process, which constitutes a way to prevent effectively the formation of biofilms on surfaces. This is true both under conditions where bacteria are able to multiply (nutritive environments) and when growth is sluggish. The use of bacteriophages for that purpose remains at this time largely unexplored despite the major benefits that it could represent, not only because of the absence of harmful effects like those related to toxicity of antibiotics and other antimicrobial molecules, but also because the bacterial resistance to bacteriophages should be easier to avoid/inhibit with employing adequate cocktails of phages. Altogether, this offers a promising alternative to the conventional use of antibiotics. The design of a new antibacterial biomaterial made of polyelectrolytes functionalized by phages, requires a fundamental study of the physicochemical properties of the polymeric matrices (PEM), the transport processes (storage/release) of the phages in the PEMs and their infectious capacities with respect to targeted bacteria. Understanding the mechanisms that govern these transport phenomena, storage and salting out of the phages within/from the PEM matrix is necessary to develop and optimize biomaterial functionalization. It is anticipated that the successful realization of such a biofunctionalized material would be of major interest in applied sciences related to e.g. water transport issues, agrobusiness, biomedicine and pharmacy.

Biofilm surface contamination represents great concerns in human health and industry. It is estimated that biofilms cause >100 000 deaths/year in Europe. Despite many efforts, current antibiofilm strategies still fail mainly because: i) they are too specific; ii) surface grafting deactivate antimicrobials; iii) antimicrobials cannot withstand successive contaminations (not renewable and “one shot” activity). The SCAZYM project aims to elaborate a large-spectrum, efficient and sustainable antibiofilm surface coating. To achieve this goal, an innovative bio-inspired strategy will be elaborated, relying on the simultaneous actions of various antimicrobial enzymes assembled on a proteinaceous scaffold. This architecture is inspired by the structure of bacterial nanomachines whose mode of action will be hijacked to synthetize biocatalytic antibiofilm coatings. The original assembly of antimicrobial enzymes on a scaffold will allow their multi-targeting action at each functionalized spot. Moreover, their grafting -via stable and reversible ligand-receptor interaction- will ensure a solid but yet renewable activity that could be added ad hoc depending on the contamination risk. To achieve this goal with a precise understanding and control of the antibiofilm action, I will use an interdisciplinary approach integrating biochemistry, microbiology and surface chemistry and an original methodology based on atomic force microscopy and vibrational spectroscopy. This project will have strong scientific, societal and economic impacts. From a fundamental perspective, the project will allow deciphering key phenomena at the cell and material interfaces, i.e. where functional molecular mechanisms occur. In medicine and industry, it is confidently expected that the new bio-inspired multienzymatic coating will offer efficient and long-term antibiofilm protection. Finally, the underlying concepts for surface functionalization may offer significant advantages in enzyme-based biotechnology.

Microelectrochemical actuators are attractive for artificial intelligence due to the dynamic tunable interactions for human-machine interface. In order to achieve high performance electro-mechanical transductive actuator using electrochemical driving force, high ion storage of electrodes play an important role. However, current electrochemical actuators suffer from low energy transduction efficiency (typically lower than 1%). In this project, we propose to develop functionalized two-dimensional MXene nanomaterials as the conductive electrode for electrochemical actuator. We have recently shown the multilayer MXene serving as effective photothermal actuator. Functionalization of MXenes provides additional degree of freedom to tailor the ionic adsorption, intercalation, and storage capacities, which could enhance the electrochemical actuator performance. We will develop an analytical methodology based on the combination of scanning electrochemical probe techniques with force sensing for studying the mechanism and dynamic electrochemical-force actuation relationship at microscale. This will deepen the scientific understanding of the material by correlating the local electrochemical and force behavior with macroscopic electrode performance, as well as guide the optimization for achieving high performance. As a further step, tailorable actuator configuration with shaping, patterning, and strain engineering can be done by 3D printing of the MXene ink, and the developed microscale analytical methodology will serve to provide quality control for the printed structures. This project will target at MXene-based actuators that can produce a large bending/expansion strain (>1.5% or 10%, respectively), high blocking force of more than 5 mN and response at high frequencies up to 1 Hz under an extended driving voltage (1.5-3 V). Finally, we will demonstrate the assembly of functionalized MXene at device level, by constructing a prototype Braille that can be applied as a flexible soft tactile display for the blind.

The PhotoMatOn project, based on a multidisciplinary consortium, is aimed to the design, the synthesis and the characterization of hybrid photocatalysts dedicated to then organic synthesis. Such novel systems will be accessed through the functionalization of porous material with photoactive organic or transition metal-based complexes. The chemical, physical and photophysical properties of these new generation hybrid photocatalysts will be studied in the context of heterogeneous catalysis where the material will play a crucial role. An electrochemical aspect will be consider in the regeneration of the catalysts as well as its participation to the photocatalytic events.Taking advantage of the porous material properties (confinement, redox, chirality…) challenging organic reactions will be investigated.