A Novel Non-Enzymatic Sensor Based on Bismuth Molybdate @polydopamine-Gold Nanocomposites for Efficient Nitrite Sensing

Novel Bismuth molybdate@polydopamine-Au nanocomposites (Bi2MoO6@PDA-Au) were synthesized and used to construct a sensor for enhanced electrochemical determination of nitrite (NO2−). Bi2MoO6@PDA-Au was investigated with scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectroscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and the results showed a large number of Au nanoparticles were uniformly distributed on 3D Flowerlike Bi2MoO6 microspheres coated with PDA. Electrochemical techniques were employed to study electrochemical performance, and the results revealed that the sensor has an excellent response to NO2− with a comprehensive linear range of 0.3 μM to 4.4 mM, which is an order of magnitude wider than that obtained by the CQD-PEDOT/GCE and two orders of magnitude wider than that obtained by the Au-MoS2/GCE. In addition, the sensor also displayed good reproducibility, reusability, long-termstability, fast response time, and anti-interference performance. It is expected that Bi2MoO6@PDA-Au nanocomposites could be a promising material in the practical efficient detection of NO2−.