Highly sensitive and selective 2-nitroaniline chemical sensor based on Ce-doped SnO2 nanosheets/Nafion-modified glassy carbon electrode

In this paper, pure SnO2 and Ce-doped SnO2 nanosheets were synthesized through a facile hydrothermal method. The synthesized materials were characterized by different techniques for their physico-chemical properties. The XRD data indicated the characteristic tetragonal rutile crystal phase for SnO2. Ce doping was ascertained by the presence of the diffraction peaks of CeO2 in all the doped samples of the SnO2 nanosheets. FESEM images revealed highly rough surfaces as well as the agglomeration of a large number of small nanoparticles of multiple shapes to form nanosheets like morphologies for pure SnO2 and Ce-doped SnO2. Electrochemical techniques like cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry were applied to demonstrate the electrochemical performances of the pure SnO2 and Ce-doped SnO2 nanosheets/Nafion-modified glassy carbon electrode (GCE). The 3% Ce-doped SnO2 nanosheet/Nafion-modified GCE showed a remarkable sensitivity of 0.9986 mu A mu M-1 cm(-2) over a linear dynamic range of 0.5-20.3 mu M. The corresponding linear regression equation was Ip (mu A) = 0.0709 [2-nitroaniline (mu M)] + 0.1385 with R-2 = 0.99325. The LOD of the modified sensor was found to be 6.3 +/- 0.1 nM at the signal-to-noise ratio of S/N = 3. The newly developed sensor electrode exhibited good selectivity toward 2-nitroaniline in the presence of common interfering species.