Magnetic graphene oxide decorated with chitosan and Au nanoparticles: synthesis, characterization and application for detection of trace rhodamine B

Abstract

A novel magnetic graphene oxide modified with Au nanoparticles (Fe₃O₄@CS/GO/Au) as an efficient adsorbent was prepared for the detection of rhodamine B (RB) coupled with fluorescence spectrophotometry. The as-prepared Fe₃O₄@CS/GO/Au was characterized by using a field emission scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS), and vibrating sample magnetometer (VSM). The main parameters, which affect extraction and desorption efficiencies, were systematically investigated and optimized. Under the optimal conditions, good linearities (0.1–6.0 μg L⁻¹) with R² = 0.9990, LODs (0.03 μg L⁻¹) and LOQs (0.1 μg L⁻¹) were achieved. Compared with chitosan-coated magnetic nanoparticles (Fe₃O₄@CS) and graphene oxide-modified Fe₃O₄@CS (Fe₃O₄@CS/GO), Fe₃O₄@CS/GO/Au exhibited optimal extraction efficiency. To demonstrate the application potency of Fe₃O₄@CS/GO/Au, it was successfully applied to isolate and extract RB from tap water, waste water, soft drink and eye shadow and the spiked recoveries were between 94.51% and 101.24% with RSD values from 1.95% to 6.15%. It was confirmed this novel method was an efficient pretreatment and enrichment procedure and could be successfully applied for the extraction and determination of trace RB in complex matrices.