Amperometric sensing of nitrite at nanomolar concentrations by using carboxylated multiwalled carbon nanotubes modified with titanium nitride nanoparticles

Muthaiah Annalakshmi; Paramasivam Balasubramanian; Shen-Ming Chen; Tse-Wei Chen

doi:10.1007/s00604-018-3136-4

Amperometric sensing of nitrite at nanomolar concentrations by using carboxylated multiwalled carbon nanotubes modified with titanium nitride nanoparticles

Mikrochim Acta. 2018 Dec 10;186(1):8. doi: 10.1007/s00604-018-3136-4.

Authors

Muthaiah Annalakshmi¹, Paramasivam Balasubramanian¹, Shen-Ming Chen², Tse-Wei Chen^{1

3}

Affiliations

¹ Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 106, Taiwan, Republic of China.
² Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 106, Taiwan, Republic of China. smchen78@ms15.hinet.net.
³ Research and Development Center for Smart Textile Technology, National Taipei University of Technology, No.1, Section 3, Zhongxiao East Road, Taipei, 106, Taiwan, Republic of China.

PMID: 30535857
DOI: 10.1007/s00604-018-3136-4

Abstract

A glassy carbon electrode (GCE) was modified with a nanocomposite prepared from carboxylated multiwalled carbon nanotubes (c-MWCNT) and titanium nitride (TiN) nanoparticles to obtain a sensor for nitrite. The nanocomposite was characterized by transmission electron microscopy, elemental mapping, X-ray diffraction, and Raman spectroscopy. Electrochemical studies results show the modified GCE to possess a low electrochemical resistance (Rct = 7 Ω) and a large electroactive surface (A = 0.112 cm²). The heterogeneous electron transfer rate (k_s) is found to be 1.26 × 10^-2 cm s^-1. Due to the excellent synergistic effect of c-MWCNT and TiN, the GCE displays and excellent performance in terms of nitrite sensing. At a typical working voltage of +0.8 V (vs. Ag/AgCl), the limit of detection (LOD) is as low as 4 nM, and the useful analytical range extends from 6 nM to 950 μM. This is much better than the LODs of previously reported nitrite sensors. The sensor is fast (response time 4 s), selective, and long-term stable. It was applied to the determination of nitrite in spiked water and meat samples and gave good recoveries. Graphical abstract Schematic presentation of electrochemical determination of nitrite using carboxylated multiwalled carbon nanotubes modified with titanium nitride nanoparticles modified electrode.

Keywords: Electrochemical sensor; Heterogeneous electron transfer rate; Inorganic pollutants; Low impedance; Methemoglobinemia.