Design and fabrication of rGO supported cobalt ferrite hybrid sensor for ultrasensitive detection of testosterone

The critical role of testosterone in various physiological and pathological processes has driven the development of highly sensitive and reliable electrochemical sensors for its ultrasensitive detection. In this study, we present a novel electrochemical sensor designed for detecting testosterone, utilizing a nanocomposite made of CoFe₂O₄ nanoparticles and reduced graphene oxide (CoFe₂O₄/rGO). The CoFe₂O₄/rGO composite was synthesized through a two-step process: CoFe₂O₄ nanoparticles were prepared via a straightforward coprecipitation method involving metal–organic framework (MOF) formation, and reduced graphene oxide (rGO) was synthesized from covalent organic frameworks (COFs) through an oxidation–reduction process. We thoroughly examined its morphology and crystal structure using SEM, TEM, and Powder XRD techniques, revealing the formation of spherical CoFe₂O₄ nanoparticles with an FCC crystal structure attached to the surface of rGO nanosheets. The rGO/CoFe₂O₄ modified Pencil Graphite Electrodes (PGE’s) electrochemical performance was evaluated using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) techniques under optimal conditions. The findings revealed that the rGO/CoFe₂O₄ modified PEG electrode demonstrated effective performance for testosterone detection in 0.1 M PBS solution, showing linear electrochemical responses to testosterone concentrations between 100 nM and 70,000 nM, with a detection limit of approximately 43 nM. From the first linear range, the limit of detection (LOD) and limit of quantification (LOQ) were determined to be 43 nM and 130 nM, respectively. Additionally, the sensor demonstrated excellent repeatability, stability, and reproducibility, with a relative standard deviation (RSD) of less than 0.7% across multiple tests. Moreover, the fabrication process is straightforward and cost-effective, highlighting the practical advantages of this approach. This work emphasizes the potential of the rGO/CoFe₂O₄ hybrid sensor as a reliable and efficient tool for testosterone detection in clinical and diagnostic applications.

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