Fabrication of chitosan-coated calcium tungstate (CaWO4/Chitosan) and its Antioxidant, antimicrobial and phocatalytic activity

In the present era, the applicability of natural bioactive polymers, such as chitosan, has become a significant concern due to its biologically compatible range, ease of biodegradability, and lower hazardous traits. In our investigation, the production of chitosan-coated calcium tungstate (CaWO4/Chitosan) was carried out using a sol–gel protocol. The resulting chitosan-coated calcium tungstate (CaWO4) was subjected to FTIR spectral analysis to identify the functionally active groups in chitosan interacting with calcium tungstate. X-ray analysis revealed the amorphous nature of chitosan-coated calcium tungstate (CaWO4), with a crystallite size ranging from 14.2 nm to 32.0 nm. The surface morphology and size of the CaWO4/Chitosan was analysed using SEM and TEM studies. The chitosan-coated calcium tungstate (CaWO4) exhibited a profound dose-dependent antioxidant activity, as determined by the DPPH assay. Both E. coli and S. aureus were susceptible to chitosan-coated calcium tungstate (CaWO4), showing inhibition zones of 19 mm and 20 mm, respectively. Additionally, chitosan-coated calcium tungstate (CaWO4) demonstrated antifungal activity against pathogenic fungi (A. flavus and A. niger) with inhibitory zones of 11 mm and 15 mm. UV-DRS analysis yielded a unique peak at 234 nm, corresponding to a band gap of 3.9093 eV. The chitosan-coated calcium tungstate (CaWO4) exhibited outstanding photocatalytic activity on alizarin, influenced by dye catalyst and concentration.