Fabrication of highly sensitive ethanol sensor based on doped nanostructure materials using tiny chips

Abstract

Doped CuO–Fe₂O₃ nanocubes (NCs) are prepared via a facile wet-chemical process using active reactant precursors with reducing agents in high pH medium (pH > 10). The NCs are totally characterized in detail using various methods, such as FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), dynamic light scattering (DLS), powder XRD, UV/vis spectroscopy, FESEM coupled XEDS, FE-SEM, etc. A thin-layer of NCs is deposited on tiny chips (surface area, ∼0.02217 cm²) to fabricate a selective ethanol sensor with short response time in liquid-phase medium. The fabricated chemi-sensor also exhibits higher sensitivity, large dynamic concentration ranges, long-term stability, and improved electrochemical performance towards ethanol. The calibration plot is linear (r² = 0.9937) over a wide ethanol concentration range (0.1 nM to 0.1 mM). The sensitivity and detection limit are ∼7.258 μA cm⁻² mM⁻¹ and ∼0.08 ± 0.02 mM (SNR, signal-to-noise ratio of 3), respectively. This novel effort establishes a well-organized way of developing efficient nanomaterial-based sensors for toxic pollutants in environmental and health-care fields on large scales.