Agata Michalska
University of Warsaw, Department of Chemistry
Agata Michalska holds PhD and DSc degrees from the Faculty of Chemistry, Warsaw University. Since 2012 she is a Professor at the Faculty of Chemistry, Warsaw University. Her current research interest includes electroanalytical and optical sensors, application of micro- and nanostructures in analytical chemistry, especially optimization of ion-selective sensors construction and analytical parameters, as well as development of nanoscale sensors. She has published over 100 scientific papers.
Nanostructures of conducting polymers draw significant research attention, with a special emphasis on applications1. However, the methods for conducting polymer nanoparticle synthesis often require application of matrices. As a consequence the surface of resulting nanoparticles is compromised – the charge and/or ion exchange between nanoparticles and environment is hindered.
We propose a novel, alternative synthetic approach - template-free method, that yields nanoparticles of narrow size distribution and high electrochemical activity due to unblocked surface2. The method takes advantage of polymeric microparticles (e.g. polyacrylate or poly(vinyl chloride)) to deliver monomer of future conducting polymer to the polymerization reaction, oxidized – positively charged nanoparticles of polypyrrole or poly(3,4-ethylenedioxytiophene) form stable suspension in solution. The nanospheres synthesis conditions can be modified to functionalize particles e.g. by incorporation of fluorescent dyes.
The high electrochemical activity of obtained conducting polymer nanospheres: unblocked, reactive, surface and optionally presence of dyes opens novel possibilities of their application to improve existing or proposes novel electrochemical or optoelectronic devices and sensors. Conducting polymers can be used either as layers formed from nanoparticles e.g. by casting or spaying or in suspension. The source of analytical signal can be either change in electrochemical properties of the nanoparticles or change of the emission of dye embedded in the nanoparticles. To highlight the benefits of herein described method of conducting polymer nanoparticles synthesis, the following model systems have been tested:
(i) optical readout of conducting polymer oxidation state change: the change of solution redox potential or alteration of potential applied to the layer of nanoparticles can be observed as modulation of emission of fluorescent dye introduced to nanoparticles.
(ii) electrochemical sensors benefiting from high electrical conductivity of layers prepared from nanoparticles: e.g. ion-selective electrodes where nanoparticles have been used to obtain electrical leads and transducers, resulting in improved sensors.
References
1. Yoon, H.; Choi, M.; Lee, K. J.; Jang, J. Macromol. Res., 2008, 16, 85
2. Kłucinska, K.; Jaworska, E.; Gryczan, P.; Maksymiuk, K.; Michalska A. Chem. Commun., 2015, 51, 12645
Nanoelectronic systems, components & devices , Metamaterials for optic & optoelectronic applications , Nanosensors
