Electrochemical-based amine functionalized gold nanoparticles decorated on nanosheets for normetanephrine detection in plasma and serum

Metals and metal oxide composites are prominent materials for detecting biomolecules in body fluids through electrochemical methods. In this study, iron-cobalt nanosheets (FeCoNS) decorated with glucosamine-functionalized gold nanoparticles (Gln-AuNPs) were synthesized to detect normetanephrine (NMN) in human plasma and serum samples. The morphology and chemical composition of the Gln-AuNPs@FeCoNS were analyzed via high-resolution transmission electron microscopy, field-emission scanning electron microscopy, atomic force microscopy, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. A glassy carbon electrode (GCE) was modified with Gln-AuNPs@FeCoNS, exhibiting high electrochemical activity for determining NMN in phosphate buffer saline (PBS) and in real samples. Importantly, the increase in the oxidation current during the reaction between the GCE modified with Gln-AuNPs@FeCoNS and NMN enabled the detection and quantification of NMN. Cyclic voltammetry, differential pulse voltammetry, and amperometry (i-t) were used to assess the sensing performance of the GCE modified with Gln-AuNPs@FeCoNS. The fabricated sensor was highly sensitive toward NMN, with a limit of detection of 0.066, 0.085, and 0.7 µM in PBS, plasma, and serum samples, respectively. The proposed electrochemical sensor provides a new platform for utilizing active metal-based catalysts to detect various biomolecules. [Display omitted]