Multi-spectroscopic and thermodynamic profiles on HSA binding of Cassia fistula leaf based potential antibacterial and anticancer silver nanoparticles

Abstract

Here, a simple, one step, lucrative and green synthesis of Cassia fistula leaf extract inspired antibacterial silver nanoparticles (CF-SNPs) was provided. Characterization of these CF-SNPs were achieved by using various spectroscopic techniques for instance Ultraviolet Visible (UV-Vis) Spectroscopy, Fourier-Transform Infrared (FTIR) Spectroscopy, Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX). The effective antibacterial action of the CF-SNPs was checked against Escherichia coli (E. Coli) DH5-Alpha where MIC was 1.6 nM. Anticancer dynamism of the CF-SNPs was also tested in opposition to skin melanoma, A375 cell lines in which 4.4 nM was IC₅₀. The binding proneness of HSA towards CF-SNPs was investigated by means of UV-Vis Spectroscopy, Fluorescence Spectroscopy, Time Resolved Fluorescence Spectroscopy, Circular Dichroism (CD) Spectroscopy, Dynamic Light Scattering, and Isothermal Titration Colorimetry (ITC). CD spectroscopy established minor secondary structural exchange of HSA in HSA-CF-SNPs complex. ITC and Time Resolved Fluorescence Spectroscopy verified the static type quenching mechanism involved in HSA-CF-SNPs complex. The binding constant was 3.45 × 10⁸ M⁻¹ at 298.15K from ITC study. The thermodynamic parameters showed that the interaction was occurred spontaneously by the hydrophilic forces and hydrogen bonding.

Communicated by Ramaswamy H. Sarma

Keywords:

• Green synthesis
• silver nanoparticle
• antibacterial activity
• anticancer activity
• circular dichroism
• isothermal titration colorimetry

Disclosure statement

No potential discrepancy of interest had been reported by the authors.

Additional information

Funding

This work is financially supported by Department of Science & Technology and Biotechnology, Government of West Bengal, India, sanction No: 1852(Sanc.)/ST/P/S&T/15G-3/2019. We thankfully acknowledge the Department of Chemistry and USIC, Vidyasagar University for their instrumental services from DST-FIST programs.