Multiwalled carbon nanotube based ion imprinted polymer as sensor and sorbent for environmental hazardous cobalt ion

ABSTRACT

By using molecular imprinting approach, a highly selective multiwalled carbon nanotube based electrochemical sensor for Co(II) ion was fabricated. The sites for binding of Co(II) ion was created with cobalt ion as template, NNMBA-crosslinked polyacrylic acid as the solid polymer matrix which is coated on functionalized MWCNTs. For the comparison, system without template was also created (MWCNT-NIP). In order to check the importance of MWCNTs, imprinted (IIP) and non-imprinted (NIP) polymer without MWCNTs were also produced. The developed systems were successfully characterized by different analytical techniques. The selectivity of the systems was checked with different metal ions. The electrochemical response of the nanostructures modified platinum electrode were investigated and optimized. The MWCNT-IIP/Co/PE exhibit fast sensing and high selectivity towards Co(II) ion. The detection limit of the sensor was explored with differential pulse voltammetry and it was found to be at 1.01 × 10⁻⁵µM. The practical applicability of the sensor was successfully applied for the trace sensing and extraction of Co(II) ion from real samples such as fertilizer and battery. The recoveries of Co(II) ion from the samples were very high, that revealed the efficiency of the systems for environmental applications.

KEYWORDS:

• Co(II) ion
• electrochemical sensing
• ion imprinting
• multiwalled carbon nanotube
• extraction

Conflict of interest

The authors hereby declare that there is no conflict of interest regarding this paper.

Acknowledgment

Maria Sebastian acknowledges the valuable support from the Kerala State for giving KSCSTE (Kerala State Council for Science, Technology and Environment) research fellowship.