Cu-nanoparticles@ graphene nanocomposite: A robust and efficient nanocomposite for micro-solid phase extraction of trace aflatoxins in different foodstuffs

Cu-nanoparticles-immobilized graphene (Cu@G) nanocomposite was fabricated in this study by reducing Cu(II) ions in the presence of graphene oxide using a simple chemical reduction step. Cu@G nanocomposite was applied as a sorbent for the SPE of four aflatoxins (AFs). A reusable syringe was filled with the fabricated nanocomposite and used as a sorbent for the micro-solid phase extraction of four AFs (AFB1, AFB2, AFG1, AFG2). The impact of different analytical factors was fully investigated and optimized. Excellent recoveries, ranging from 92.0 to 108.5 %, were detected when evaluating target AFs in samples of rice, maize, and pistachio. The LOD, LOQ, and linear ranges were attained under optimal circumstances in the ranges of 0.0062 mu g kg-1, 0.0192 mu g kg-1, and 0.0-20 mu g kg -1, respectively. The discovered approach provided the dual benefits of a high enrichment capability of Cu-nanoparticles via AFs complexation and a huge porosity of graphene sheets.