A chemiresistor sensor modified with lanthanum oxide nanoparticles as a highly sensitive and selective sensor for dimethylamine at room temperature

Abstract

Lanthanum oxide nanoparticles were synthesized by a simple reverse micelle method and characterized by X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area measurements, particle size distribution (PSA), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The lanthanum oxide nanoparticles were coated on an interdigitated microelectrode (IDE) surface by the drop-coating method. The sensor response was investigated by measuring the electrical resistance of the sensor when dimethylamine gas was inserted into the test chamber. Within the 3–3300 mg L⁻¹ concentration range, the sensor response and recovery times were 27–184 s and 3–10 s, respectively. The results indicated that the La₂O₃ sensor exhibited an amazing performance in the detection of dimethylamine gas at room temperature and provided a significant response (R_g/R_a = 7.4) for 100 mg L⁻¹ of dimethylamine gas.