Abstract
Heliotropium crispum mediated silver nanoparticles provide a cost-effective nano-fluid that have tendency to formulate potent anti-bacterial and anti-biofilm formulations.
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•Heliotropium crispum extract acts as a cost effective biomaterial for AgNPs assembly.•Plant extract mediated synthesis provide therapeutic functional groups capping to AgNPs.•AgNPs cause cell wall mediated destruction of pathogenic bacterial strains.•Potent anti-biofilm response of AgNPs was observed up to 72h of incubation.
The study describes the optimized method for silver nanoparticle (AgNPs) synthesis using Heliotropium crispum (HC) plant extract. Optimization of physicochemical parameters resulted in stable and rapidly assembled AgNPs. FTIR results suggest presence of plant phytochemicals that helped in the reduction, stabilization and capping of AgNPs. The assembled Ag nano-composites displayed the peak surface plasmon resonance (SPR) around 428nm. The presence of uniquely assembled Ag-biomolecule composites, cap and stabilize nanoparticles in aqueous plant suspension. Spherical, uniform-shaped AgNPs with low poly-dispersion and average particle size of 42nm and was determined through dynamic light scattering (DLS) and scanning election microscopy (SEM) which present robust interaction with microbes. The study also evaluates the antimicrobial and anti-biofilm properties of biologically synthesized AgNPs on clinical isolates of MRSA, Pseudomonas aeruginosa and Acinetobacter baumannii. Minimum inhibitory concentration (0.5mgmL−1) of nanoparticles that presented bactericidal effect was made through inhibition assays on bacterial strains. The concentration which presented potent bactericidal response was then evaluated through growth inhibition in liquid medium for anti-biofilm studies at 2.0mgmL−1. HC-Ag nanoparticles mediated anti-biofilm effects on Pseudomonas aeruginosa was revealed through SEM. Complete breakdown of biofilm’s extracellular polymeric substances resulted after incubation with AgNPs. Peptidoglycan cell wall destruction was also revealed on planktonic bacterial images after 24h of incubation.