Exploration on structural and optical properties of nanocrystalline cellulose/Poly(3,4-Ethylenedioxythiophene) thin film for potential plasmonic sensing application

• Main Authors: Md Ramdzan, Nur Syahira, Yap, Wing Fen, Ying, Josephine Chyi Liew, Sheh Omar, Nur Alia, Anas, Nur Ain Asyiqin, Mohd Daniyal, Wan Mohd Ebtisyam Mustaqim, Muhamad Fauzi, Nurul 'Illya
• Format: Article
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2021
• Online Access: http://psasir.upm.edu.my/id/eprint/97208/1/ABSTRACT.pdf; http://psasir.upm.edu.my/id/eprint/97208/; https://www.mdpi.com/2304-6732/8/10/419

There are extensive studies on the development of composite solutions involving various types of materials. Therefore, this works aims to incorporate two polymers of nanocrystalline cellulose (NCC) and poly(3,4-ethylenethiophene) (PEDOT) to develop a composite thin film via the spin-coating method. Then, Fourier transform infrared (FTIR) spectroscopy is employed to confirm the functional groups of the NCC/PEDOT thin film. The atomic force microscopy (AFM) results revealed a relatively homogeneous surface with the roughness of the NCC/PEDOT thin film being slightly higher compared with individual thin films. Meanwhile, the ultraviolet/visible (UV/vis) spectrometer evaluated the optical properties of synthesized thin films, where the absorbance peaks can be observed around a wavelength of 220 to 700 nm. An optical band gap of 4.082 eV was obtained for the composite thin film, which is slightly lower as compared with a single material thin film. The NCC/PEDOT thin film was also incorporated into a plasmonic sensor based on the surface plasmon resonance principle to evaluate the potential for sensing mercury ions in an aqueous medium. Resultantly, the NCC/PEDOT thin film shows a positive response in detecting the various concentrations of mercury ions. In conclusion, this work has successfully developed a new sensing layer in fabricating an effective and potential heavy metal ions sensor.