Gene

Surface plasmon resonance

Nuclear chemistry

Nanoparticle

Nanotechnology

Chemistry

Materials science

Nanobiotechnology

Serratia marcescens

Antibacterial activity

Silver nitrate

Silver nanoparticle

Bacteria

Genetics

Escherichia coli

Biochemistry

Biology

Microbiology

Heliyon

<h2>Abstract</h2> The non-hazardous silver nanoparticles (AgNPs) synthesised using the extract of a biological organism has gained widespread attention for various applications, mainly in healthcare. This study aimed at synthesising AgNPs using the aqueous extract of Marphysa moribidii (Annelida, Polychaeta) and to evaluate their antibacterial activities. AgNPs were synthesised in response to silver nitrate (AgNO3) with polychaete crude extract for 24 h incubation; the polychaete crude extract acted as both reducing and stabilising agents. The presence of biosynthesised AgNPs was confirmed by an analysis of colour variations from pinkish to yellowish-brown, as well as the appearance of surface Plasmon resonance (SPR) bands at 398–400 nm using ultraviolet-visible spectroscopy. Biosynthesised AgNPs were characterised by dynamic light scattering, scanning electron microscope, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Biosynthesised AgNPs showed a significant effect (p < 0.05) on Gram-positive bacteria (Staphylococcus aureus and S. epidermidis) and Gram-negative bacteria (Escherichia coli, Klebsiella pnemoniae, Salmonella typhimurium, Serratia sp., Shigella sonnei, and Pseudomonas aeruginosa). Thus, the crude extract of M. moribidii has a potential as a reducing agent for the development of future nanometal-based antibacterial agent, AgNPs, for the treatment of infectious diseases caused by pathogenic bacteria.

Eco-friendly silver nanoparticles (AgNPs) fabricated by green synthesis using the crude extract of marine polychaete, Marphysa moribidii: biosynthesis, characterisation, and antibacterial applications