High performance acute toxic methanol sensor based on hydrothermally prepared hexagonal nanodiscs (NDs) of ZnO/CdO/SnO2 (ZnCdSnO2 or ZCSO) was fabricated onto glassy carbon electrode (GCE). The characterization of ZCSO NDs in-terms of functional group analysis, binding energy evaluation, oxidation states, optical absorbance, crystallinity, structural morphology, and elemental compositions were performed by FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), UV–visible spectroscopy, XRD, FESEM-coupled-EDS analysis respectively. The current versus concentration plot was exhibited linear on a wide range of methanol concentration (0.01 nM to 0.1 mM) clarified as linear dynamic methanol detection range (LDR). Considering the ZCSO NDs-coated surface area onto GCE over the slope of LDR, noticeable methanol sensor sensitivity (4.5475 µA µM−1 cm−2) was perceived. Besides this, a considerable lower limit (7.69 ± 0.38 pM) of detection at signal/noise = 3 is obtained. The overall results of methanol chemical sensor were found with satisfactory and acceptable results in terms of their reproducibility, sensitivity, stability, and response-time. Additionally, the assembled ZCSO NDs-coated electrode was validated with real environmental samples and result was found good and acceptable. On considering the outcome of applicability and the way of this sensor assembling, this unique method might be a potential technique in the field of portable sensor development for the safety of environmental and healthcare fields in a broad scale.