Unveiling Intrinsic Iron of Pencil Graphite in FeS2 Formation and Its Sensing Applications

The synthesis of nanomaterials in novel ways is always an attractive and challenging to the researchers. In this regard, the development of a new approach is a persistent investigation. Herein, we report the solvothermal growth of iron dichalcogenide (FeS
$_{{2}}\text {)}$
by using the intrinsic iron of commercially available pencil [pencil graphite (PG)] and sulfur from thiosulfate as only precursor (i.e., FeS2@PG). Furthermore, the physicochemical characterization (SEM-EDX, XRD, and Raman) of the hybrid material revealed the morphology of FeS2 as a cube and available in its pyrite phase. Likewise, the electrochemical studies of cyclic voltammetry (CV) and EIS also evident the possibility of the FeS2@PG for the detection of uric acid (UA) as a model analyte in physiological pH 7.4 phosphate buffer solution (PBS). The electrochemical studies of the FeS2@PG toward UA displayed a sensitivity of 0.131 A M
$^{-{1}}$
and a detection limit of
$4.58~\mu $
M in 5–1800-
$\mu $
M linear range. FeS2@PG sensor also displayed excellent linearity, reproducibility, and selectivity toward UA over the other co-exisiting electroactive biochemical, such as glucose and ascorbic acid. This could be attributed due to the electrocatalytic active sites of FeS2 exists over the surface of PG. To validate the efficiency of FeS2@PG toward the detection of UA, human urine sample is considered as a real sample and compared with the conventional colorimetric technique. Overall, this research work will provide the new possibilities in the synthesis of iron-based nanomaterials and their applications.