Biological activities of chitosan-salicylaldehyde schiff base assisted silver nanoparticles

Abstract

Objectives: The nanobiotechnology era has sparked interest in the green synthesis of stable silver nanoparticles (Ag-NPs) without hazardous chemicals. As a result, the current study used chitosan-salicylaldehyde Schiff base (CSB) as a non-toxic, reducing and stabilizing agent to prepare stable silver nanoparticles. Methods: The characterization of Ag-NPs impregnated chitosan-salicylaldehyde Schiff base was fulfilled using UV-Vis, FTIR, XRD and TEM studies. Results: The absorption band present around 425 nm in UV-Vis spectra indicated the formation of Ag-NPs. The appearance of a new band for the CN bond, deduction in the intensity of the CO group of salicylaldehyde and NH group of chitosan confirmed the formation of Schiff base and Ag-NPs in FTIR analysis. XRD pattern revealed the orientation and crystalline nature of Ag-NPs with 2θ at 38°, 46° and 54° related to Ag-NPs (JCPDS No. 04-0783), whereas the peak at 2θ = 27° associated with CSB. The total porosity of 53.24% was determined using the liquid displacement method. The CSB-Ag-NPs have good scavenging activity (46.25% and 49.35% activity in DPPH assay and H2O2 assay), great antibacterial (zone of inhibition 17 mm and 19 mm for E-Coli and Pseudomonas sp.), antifungal (18 mm for P. notatum), and anti-larvicidal activity, according to biological assessments. Conclusions: The synthesised Ag-NPs were non-toxic to marine ecosystems in a safety bioassay test.

Keywords

• Silver nanoparticles
• Chitosan
• Schiff base
• Salicylaldehyde
• Biological assay
• Biosafety assay