The central theme of this work is the synthesis of single-walled carbon nanotubes (SWCNTs) through the chemical vapor deposition method (CVD). Single-walled carbon nanotubes are synthesized using catalyst-chemical vapor deposition of acetylene at 750 °C temperature. X-ray diffraction study gives a characteristic peak (002) at 26.55° corresponding to the existence of carbon nanotube confirms that the particles are crystalline in nature and hexagonal phase. An SEM and HRTEM outcome gives surface morphology of SWCNTs. The elemental composition was confirmed by EDAX. The ideal concentration of single-walled carbon nanotubes was used to design a novel electrochemical sensor for determining paracetamol (PA) using cyclic voltammetry. Electrochemical determination of paracetamol is described using a single-walled carbon nanotube modified carbon paste electrode (SWCNT/MCPE). The SWCNT/MCPE was used in this study to detect paracetamol electrochemically at pH 7.2 in a 0.2 M PBS with a scan rate of 50 mV s− 1. A single-walled nanotube modified carbon paste electrode was used to develop a sensitive and selective electrochemical technique for the detection of PA. The SWCNT/MCPE showed excellent electrocatalytic activity towards the oxidation of paracetamol in phosphate buffer solution. Therefore, with increased oxidation currents, the voltammetric responses of paracetamol at the bare carbon paste electrode are organized within cyclic voltammetric peaks.

    Abstract
        Graphical abstract
    1 Introduction
    2 Experimental
        2.1 Apparatus and reagents
        2.2 Synthesis of SWCNTs using catalyst-chemical vapor deposition method
        2.3 Preparation bare carbon paste electrode and SWCNTs modified carbon paste electrode
        2.4 Characterization methods
    3 Result and discussion
        3.1 X-ray diffraction
        3.2 Scanning electron microscope
        3.3 Energy-dispersive X-ray spectroscopic analysis
        3.4 High-resolution transmission electron microscopy
        3.5 Effect of SWCNT on MCPE for study of paracetamol
        3.6 The electrochemical response of paracetamol at BCPE and SWCNT MCPE
        3.7 Effect of scan rate on the peak current
        3.8 Repeatability, reproducibility and stability studies
        3.9 The effect of the concentration of paracetamol
    4 Conclusion
    Acknowledgements 
    References

• A. V. Ambika(Department of Physics, B.M.S. College of Engineering (Affiliated to Visesvaraya Technological University))
• N. Navya(Department of Physics, B.M.S. College of Engineering (Affiliated to Visesvaraya Technological University))
• S. R. Kiran Kumar(Department of Chemistry, Centre for Nanoscience)
• B. L. Suresha(Department of Physics, B.M.S. College of Engineering (Affiliated to Visesvaraya Technological University))