Highly sensitive sensor probe development with ZCCO nano-capsule composites for the selective detection of unsafe methanol chemical by electrochemical technique

In this approach, an electrochemical sensor for the detection of methanol was assembled by depositing ZnO/CdO/CuO nanocapsules (ZCCO NCs) as a thin layer on the flat surface of glassy-carbon electrode (GCE) to result in the working electrode of the proposed methanol sensor probe. The characterization of wet-chemically prepared ZCCO NCs were performed by analyzing using including Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), UV–Vis Spectroscopy (UV–vis), X-Ray Diffraction Analysis (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and Energy-dispersive X-ray spectroscopy (EDS) tools. The assembled methanol sensor was performed based on I-V electrochemical method. The corresponding resultant current data were found to be linear at the current versus concentration plot in a concentration range of methanol of 0.1 mM ~ 0.01 nM, that clarified as the detection range (LDR) of the methanol sensor probe. Here, the methanol sensor sensitivity is measured using the slope of the calibration curve in LDR by considering the coated cross-sectional area (0.0316 cm2) of ZCCO on the flat part of GCE. It is obtained value as 1.7405 µAµM−1 cm−2. Besides this, the limit of methanol detection (LOD; 54.51 ± 2.73 pM) is obtained at signal/noise (S/N = 3). Moreover, the other parameters of the methanol sensor probe including reproducibility, repeatability, stability, and response time were exhibited with good results and reliability. Additionally, the assembled methanol I-V sensor probe was tested to execute the real-time application by analyzing environmental samples and found acceptable. Based on the outcome of applicability and the way of this sensor assembling, this unique I-V method might be a potential technique in the field of portable sensor development using nanostructure materials for the safety of environmental and healthcare fields in a broad scales.