Efficient hydrazine electrochemical sensor based on PANI doped mesoporous SrTiO3 nanocomposite modified glassy carbon electrode

Herein, an electrochemical approach was developed for the rapid and selective determination of hydrazine using 5% polyaniline (PANI)-doped mesoporous SrTiO3 nanocomposite modified glassy carbon electrode (GCE). The nanocomposite was synthesized by a modified sol-gel procedure using F127 structure mediator agent to obtain mesoporous SrTiO3 followed by an ultra-sonication technique to produce the final PANI doped SrTiO3. Various characterization tools, namely, XRD, XPS, FE-SEM and HR-TEM confirmed the successful formation of the nanocomposite and revealed cubic perovskite structure with d-spacing value 2.70 angstrom for mesoporous SrTiO3. Cyclic voltammetry and electrochemical impedance spectroscopy measurements exhibited higher electrocatalytic performance of the PANI/SrTiO3 nanocomposite compared to either pure SrTiO3 or unmodified GCE. The hydrazine oxidation reaction follows the first-order diffusion-controlled kinetics with a transfer coefficient value 0.65 obtained from Tafel plot analysis. Linear sweep voltammetry (LSV) and amperometric (i-t) techniques revealed that the PANI/SrTiO3 nanocomposite modified GCE exhibited remarkable sensitivity; 0.2128 mu A mu M-1 cm(-2) over the concentration range 0.2-3.56 mM (LSV) and 0.2438 mu A mu M-1 cm(-2) over the concentration range 16-58 mu M (amperometry) with a rapid response time < 10s. The limit of detection (LOD) was estimated to be 1.09 mu M and 0.95 mu M at (S/N = 3) for LSV and amperometric technique, respectively. Additionally, the modified electrode demonstrated excellent anti-interfering ability in the presence of various common active species as well as exhibited good operational stability and sutability for the real sample analysis. Such developed PANI/SrTiO3 nanocomposite represents an excellent electro-catalyst for efficient detection and quantification of hydrazine by the electrochemical approach.