Electroanalytical methods are widely used owing to their high sensitivity, but they often suffer from poor selectivity when multiple analytes are present. Charge and size selective filtering membranes are therefore necessary to induce selectivity. In this project, lignocellulosic building blocks and novel membrane architectures are utilized to develop electrochemical applications and enable realization of state-of-the-art solutions for biosensors and wastewater analytics.
For biosensors, the selectivity towards a particular analyte remains a big challenge in electrochemical sensors due to the large number of interferents typically present in biological matrices. The LA-FAST project develops hybrid lignocellulose-based filtration membranes capable of both charge and size selective exclusion of interferents is therefore necessary to improve the selectivity of these sensors for electrochemical detection of biomolecules.
Residues of pharmaceuticals in wastewater impose severe environmental and human health related problems. To tackle these challenges, LA-FAST project develops a 3D architecture consisting of nanocellulose and nanocarbon materials, integrated together to form a tunable membrane structure capable of detecting drug residues from effluents at superior sensitivity and selectivity.
Main results
We have demonstrated the potential of nanocellulose/multiwalled carbon nanotube hybrids for electrochemical sensing systems.
Choice of (nano)cellulose material governs the morphology, swelling and analyte diffusion, as well as fouling properties of the hybrid electrode
Testing of various grades of cellulose reveals that presence of either fibrillar nanocellulose or polymeric cellulose derivative enables optimal electroanalytical performance for the electrode
Controlled deposition by slow spin coating procedure results in a uniform hybrid film of <400 nm with optimized electroanalytical performance, superior to either ultrathin (<50 nm) or micron-scale layers
Publications
Liljeström, T., Kontturi, K. S., Durairaj, V., Wester, N., Tammelin, T., Laurila, T., & Koskinen, J. (2023). Protein Adsorption and Its Effects on Electroanalytical Performance of Nanocellulose/Carbon Nanotube Composite Electrodes. Biomacromolecules, 24(8), 3806-3818. https://doi.org/10.1021/acs.biomac.3c00449
Durairaj, V., Nanocellulose / Nanocarbon Composites for Direct Electrochemical Detection of Small Molecules. Aalto University publication series DOCTORAL THESES, 169/2022. https://aaltodoc.aalto.fi/handle/123456789/117994
Durairaj, V., Liljeström, T., Wester, N., Engelhardt, P., Sainio, S., Wilson, B.P. , Li, P., Kontturi, K.S., Tammelin, T., Laurila, T. & Koskinen, J., Role of Nanocellulose in tailoring Electroanalytical Performance of HybridNanocellulose/Multiwalled Carbon Nanotube Electrodes, Cellulose 29 (17), 9217–9233 (2022). https://doi.org/10.1007/s10570-022-04836-8
Durairaj, V., Li, P., Liljeström, T., Wester, N., Etula, J., Leppänen, I., Ge, Y., Kontturi, K.S., Tammelin, T., Laurila, T., and Koskinen, J., Functionalized Nanocellulose/Multiwalled Carbon Nanotube Composites for Electrochemical Applications, ACS Appl. Nano Mater. 4 (6), 5842–5853 (2021) . https://doi.org/10.1021/acsanm.1c00774