Citrate stabilized gold nanoparticles on graphenic carbon spheres for the selective detection of hydrazine

We have studied the electrocatalytic properties of hydrazine in the alkaline environment by using the stable sensor matrix. Thereby, we have selected the citrate-capped gold nanoparticles (AuNPs) decorated grapheneic carbon spheres (GCS). The hydrothermal carbonization method is utilized to prepare the GCS by using reduced graphene oxide (rGO) and glucose. In hydrothermal treatment, the glucose undergoes polycondensation and simultaneously reduced the rGO which results in spherical morphology. These spheres consist of a carbonized nucleus and a hydrophilic surface that facilitates the formation of citrate-capped AuNPs on its surface. This novel composite provides the stable platform to determine the hydrazine in pH 13. Various physicochemical techniques confirm the formation of GCS-AuNPs and also characterized by electrochemical techniques. This GCS-AuNPs modified GCE has showed the good electrochemical performance to the hydrazine oxidation. Also, it revealed the acceptable analytical performance to the determination of hydrazine. The estimated linear concentration range, limit of detection and sensitivity are 0.02 to 530.1 μM, 6 nM and 4.45 μA μM-1 cm-2. Moreover, GCS-AuNPs/GCE shows good reproducibility and good recovery in real sample analysis.