Synthesis and Characterization of Polylactic Acid (PLA)-Coated Fe3O4@CQD Nanocomposites

Abstract

This study aims to coat Fe₃O₄@CQD nanocomposites with polylactic acid (PLA) and investigate the effects of PLA concentration on their physicochemical properties, particularly fluorescence intensity and zeta potential. The results showed that PLA coating effectively increased luminescence intensity. After PLA coating, the fluorescence intensity increased dramatically, indicating reduced quenching. The results of the study show that the maximum fluorescence intensity is achieved at a PLA concentration of 2%. The sample with 2% PLA also shows a zeta potential of −32.2 mV, which is considered a relatively good colloidal stability by the widely accepted criterion of |ζ| ≥ 30 mV. SEM analysis reveals particle agglomeration, indicating that the coating does not entirely prevent aggregation. The 2% PLA formulation, therefore, shows promising physicochemical characteristics and may serve as a candidate for further investigation in bioimaging-related applications. Further biological studies are required to evaluate its biocompatibility and actual suitability for biomedical applications.