Characterization and participation of biomolecules in CdS-NPs synthesis from an aqueous extract of Fusarium oxysporum with potential application in metal detection

Fungal extracts contain biomolecules that may be used as reducing agents and stabilizers during the synthesis and coating of nanoparticles (NPs). However, fungal extracts are complex in composition; thus, specific applications can be a challenge. The present work aims to partially characterize the biomolecules present in the aqueous extract of Fusarium oxysporum , which is subsequently used for the synthesis of cadmium sulfide nanoparticles (CdS-NPs) with potential application for metal detection. The aqueous extract of Fusarium oxysporum was characterized by UPLCMS and by its ferric -reducing antioxidant power, NADH, -SH groups, and protein content as well. Synthesis of CdS-NPs was performed using the fungal extract, Cd(NO 3 ) 2 *4H 2 O, and two sulfur precursors (S degrees and Na 2 SO 3 ). Metal detection (Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) was assessed by CdS-NPs synthesized from both sulfur precursors. Chromatographic analysis evidenced the presence of compounds within 100 to 300 Da, which may be involved in CdS-NPs synthesis. It was confirmed that only CdS-NPs obtained from Na 2 SO 3 were able to qualitatively detect Co 2 + at pH 8 and Pb 2 + , Cr 6 + , and Fe 3 + at pH 4.