Pristine and Iodo-Lignin Nanoparticles Prepared via Nanoprecipitation for Antifungal Applications

• Main Author: Marshallanore, Amat
• Format: Thesis
• Language: English; English; English
• Published: Materials Letters 2023
• Subjects: QD Chemistry
• Online Access: http://ir.unimas.my/id/eprint/44733/5/Marshallanore_dsva.pdf; http://ir.unimas.my/id/eprint/44733/6/Thesis%20Master_Marshallanore%20Amat%20-24%20pages.pdf; http://ir.unimas.my/id/eprint/44733/7/Thesis%20Master_Marshallanore%20Amat.ftext.pdf; http://ir.unimas.my/id/eprint/44733/
• Institution: Universiti Malaysia Sarawak

In this study, lignin and iodo-lignin nanoparticles were prepared by nanoprecipitation method. Lignin nanoparticles (LNPs) demonstrated a decrease in particle size from 200 nm to 20 nm with an increased volume of water from 10 mL to 50 mL. Meanwhile, the obtained lignin nanoparticles are functionalised with iodine by laccase catalysed iodination. Iodo-lignin nanoparticles (I-LNPs) shows decreased nanosized from 350 nm to 40 nm with decreased volume of water (50 mL to 10 mL) after observed under SEM and TEM analysis. Further, antifungal activity was evaluated on LNPs and I-LNPs at different particles size (20 nm to 350 nm) and different concentrations (3 mM to 12 mM) against Fusarium equiseti, Cunninghamella sp., Aspergillus niger, Aspergillus flavus, Trichoderma piluliferum and Penicillium chermesinum.The maximum antifungal activity was achieved by decreasing nanosized and increasing the concentration of LNPs and I-LNPs. Mycelium inhibition of I- LNPs were greatly decreased about 65% to 98 % with decreasing nanosized and increasing concentration against the tested fungi. The best antifungal results were achieved using I- LNPs size at 40 nm combined with 12 mM concentration. Meanwhile, LNPs demonstrated lower inhibition about 20% to 75%. Similarly, the best result for LNPs was achieved using the smallest nanosized at 20 nm combined with 12 mM concentration. The potential application of LNPs and I-LNPs were further tested on bamboo by impregnation of nanoparticles via laccase catalysed reaction. The molecular results revealed the isolated fungi as Cunninghamella sp., Pleosporales sp. and P. sumatrense. Then, these fungi were tested against LNPs and I-LNPs. Interestingly, I-LNPs shows promising results about 80% to 90% of mould resistance against Cunninghamella sp., Pleosporales sp., and P. sumatrense. Further decay resistance test of I-LNPs treated bamboo shows excellent results with less than 5% of mass loss. After leaching, I-LNPs shows good decay resistance with less than 8 % of mass loss after 90 days of incubation. This work has revealed that I-LNPs and LNPs can be a potential candidate as antifungal agents against plant pathogenic fungi.