Research

Materials that are designed to change their properties under external stimuli are in great demand. Our group works on the development of two classes of stimuli-responsive materials, such as colorimetric metal ion sensors and high-performance electrochromic materials. We aim to develop materials and methods that utilize these molecular-based materials to improve the reliability of testing for heavy metal ions in the environment and biological systems. For this, we need to explore proper ligands and metal complexes, their ability to form well-packed architectures on appropriate surfaces and tune their intermolecular interactions. We also working on the improving of electronic communication between the support and the ligand and increasing the robustness of the surface-anchoring groups. See our work for more details.

Water splitting upon irradiation by light, that results in the formation of O2 and H2, makes water a portable energy source. Developing viable, stable catalysts for water splitting is critical since this reaction is truly a green, sustainable method to generate hydrogen, which is the cleanest chemical fuel known since its combustion generates only water. See our work for more details.

Design and development of efficient electrical energy storage devices with the ability to control the properties on the molecular level is crucial for modern sustainable energy systems. Creating supercapacitors of the faradaic type, called pseudocapacitors, which rely on redox reactions that induce the colour change, results in devices that show how much charge has left by simply changing their colour. See our work for more details.

The overall process of water splitting includes two half reactions, water reduction and water oxidation, generating H2 and O2 respectively. Of these, the latter is exceptionally challenging: it is endothermic, requires high (1.23V) potential, four electrons must be transferred to an electron acceptor per one molecule of generated oxygen, and the electron transfer must be carefully orchestrated. Robust water oxidation catalysts are required to produce oxygen efficiently, that is, with high rates using only a small overpotential. Catalyst stability is another key issue to solve in the quest towards a viable and relevant catalyst that can be used for large scale energy production from light and water. These observations prompted us to focus on the development of well-defined, stable molecular catalysts that are supported on reusable surfaces for oxidation of water and organic compounds.

There are several potential advantages in confining a molecular catalyst to a surface to form a heterogeneous system, including facile product purification and catalyst reusability. Beginning with a molecular catalyst, we will gain considerable insight into mechanisms of action and deactivation. A significant advantage of catalyst immobilization is the ability to control and tune the catalyst concentration on the surface. For example, the packing density of the immobilized catalyst can be engineered to be very low if unimolecular substrate activation mechanisms are preferred; or very high if bimetallic mechanisms are more desirable. Furthermore, alternative mechanism(s) of substrate activation could be operational when employing immobilized catalysts. Anchoring of transition metal complexes onto surfaces is a powerful method for the controlled preparation of materials that are otherwise inaccessible by conventional techniques. See our work for more details.

The development of artificial chemo- and biosensors, discrete molecules that selectively recognize and signal the presence of a specific analyte in a complex matrix, is one of the main achievements of supramolecular chemistry and biochemistry. The intense interest in this field is driven by the growing demand for extremely sensitive and selective analytical tools for the detection and monitoring of various substrates in biological, environmental, and industrial waste samples without the need to label these substrates. In this respect, immobilized chemosensors are of particular importance because they offer the advantage of high sensitivity, stability, reusability and require relatively simple signal-detection techniques. We will utilize SAMs on a surface as catalysts or as highly selective, molecular sensors for studying important interactions in biological objects (DNAs, metalloproteins and antibodies). Immobilization of target molecules will allow us to benefit from the opportunity to better explore particular chemical reactions by directly observing chemical modification of the surface at different stages of the reaction process.

This project will start from the preparation of novel organic SAMs terminated by nitrogen donor ligands on silicon, glass or indium tin oxide (ITO) covered surfaces. We will then modify the organic monolayer through a reaction with suitable metal precursors. In this way, we will probe the ability of simple nitrogeneous ligand terminated SAMs to work as chemosensors for particular metal ions in the solution by colorimetric, fluorescence or electrochemical methods. These surface-anchored metal complexes will be further functionalized by antimicrobial peptides able to bind to bacteria. The selectivity and specificity of this binding will be explored using incorporated metal as redox reporter.