Abstract
•NiO NPs decorated MWCNT/GCE for chloroform sensor by I–V method.•Highly sensitive (917.7nA/cm2μM) chloroform sensor.•Lowest detection limit (0.1034±0.0002nM) ever found.•Sensor development coupled with nanotechnology.•Environmental safety.
Transition metal oxide (NiO) nanoparticles decorated multi-walled carbon nanotubes (NiO/MWCNT nanocomposites, NCs) were prepared by a facile solution method using reducing agents in alkaline medium. The NiO/MWCNT NCs were characterized by UV/vis, FT-IR, energy-dispersive X-ray spectroscopy (XEDS), powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and scanning electron microscopy (TEM). The NiO NPs or NiO/MWCNTs were deposited separately on flat glassy carbon electrode (GCE) with conducting binders (5% nafion) to result in a sensor that has a fast response towards selective chloroform (CHCl3). Features including high-sensitivity, lower-detection limit, reliability, reproducibility, ease of integration, long-term stability, selective, and enhanced electrochemical performances are investigated in details. It is detailed studied the sensor performances with NiO NPs/GCE and NiO/MWCNT/GCE electrodes separately and found that NiO/MWCNT/GCE exhibits the higher sensitivity and lower detection limit compared to NiO/GCE assembly. The calibration plot is linear (r2=0.9763) over concentration range (3.5nM to 35.0mM) with NiO/MWCNT/GCE. The sensitivity and detection limit was calculated for NiO/MWCNT/GCE as ∼917.7nA/cm2μM and 0.1034±0.0002nM (at a signal-to-noise-ratio, SNR of 3) respectively. Finally, the efficiency of the proposed chemi-sensors can be applied and effectively utilized for the detection of toxic chloroform compound in environmental and healthcare fields in broad scales.
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