FinnCERES Flagship is proud to announce that on December 14, 2022, MSc. Vasuki Durairaj defended the doctoral thesis "Nanocellulose and carbon nanomaterial based hybrid electrodes for direct electrochemical detection of small molecules" and became the first Doctoral graduate who was essentially fully funded by the Flagship. The research work was carried out between February 2018 and September 2022, in the Department of Chemistry and Materials Science, School of Chemical Engineering, at Aalto University, under the supervision of Professor Jari Koskinen.
Content of the doctoral thesis
In our daily lives, we are exposed to a multitude of natural and synthetic molecules from drugs, cosmetics, food additives, pesticides, and many such sources, which can have specific interactions with the human body. Detection of such molecules using fast, simple and accurate methods is vital to our health and well-being. Electrochemical sensors, particularly those based on carbon nanomaterials, can enable highly sensitive detection of various small molecules.
Recent research has shown that nanocellulosic materials, obtained from plantbased cellulose, can effectively disperse different carbon nanomaterials in aqueous solutions. This offers a sustainable route to development of highly functional electrochemical sensors without the use of harsh chemical treatments and environmentally hazardous synthetic polymers. However, this field is relatively new, and not many studies have been published regarding the role of nanocellulosic materials upon the performance of such sensors.
The thesis focuses on using nanocellulosic materials with different geometries and functionalizations, to develop composite electrode architectures with commercial multiwalled carbon nanotubes (MWCNT). The physical and chemical nature of the nanocellulosic materials, MWCNT, and their composites, are studied using several surface and bulk characterization methods and are correlated to electrochemical performances. The nanocellulose geometry is clearly demonstrated to have a significant effect upon the composite morphology and the nature and degree of nanocellulose functionalization is shown to have a significant effect on the extent of electrostatic interactions in the composite. Further, the proposed nanocellulose / MWCNT composite electrodes are shown to clearly outperform commercial MWCNT electrodes in the selective and sensitive detection of a cationic small molecule such as dopamine.