Synthesis and characterisation of PNA conjugated chitosan coated magnetic iron oxide nanoparticles

Abstract

The present study was undertaken to synthesize and characterize of PNA conjugated chitosan coated magnetic iron oxide nanoparticles for the nanopurification of Malabari buck semen. Iron oxide nanoparticles (IONPs) have attracted increasing interest in animal reproductive biotechnology due to their magnetic properties, biocompatibility and amenability to surface functionalisation. The present study aimed to synthesise magnetite iron oxide nanoparticles (Fe?O?), functionalise them with chitosan, and bioconjugate peanut agglutinin (PNA) lectin to develop a biologically relevant nanoparticle system for buck semen nanopurification. Magnetite nanoparticles were synthesised using the chemical co-precipitation method and surface modified with chitosan to improve colloidal stability and provide reactive functional groups. Lectin conjugation was achieved through glutaraldehyde-mediated covalent crosslinking. The synthesised nanoparticles were characterised using UV-visible spectroscopy, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and zeta potential analysis. UV-visible spectroscopy confirmed nanoparticle formation and preservation of the iron oxide core following surface modification. SEM revealed quasi-spherical to irregular nanoparticles within the nanoscale range. FTIR spectra confirmed successful chitosan coating and PNA immobilisation through characteristic functional group signatures. Zeta potential analysis indicated moderate colloidal stability with a predominantly negative surface charge after lectin conjugation. These findings demonstrate the successful synthesis, functionalisation and bioconjugation of IONPs, supporting their suitability for application in semen nanopurification strategies.