Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Aug 6:12:1358353.
doi: 10.3389/fchem.2024.1358353. eCollection 2024.

Efficient nitrite determination by electrochemical approach in liquid phase with ultrasonically prepared gold-nanoparticle-conjugated conducting polymer nanocomposites

M Faisal  1   2 , M M Alam  3 , Jahir Ahmed  1   2 , Abdullah M Asiri  4   5 , Jari S Algethami  1   2 , Raed H Altholami  6 , Farid A Harraz  1   7 , Mohammed M Rahman  4   5
Affiliations

Efficient nitrite determination by electrochemical approach in liquid phase with ultrasonically prepared gold-nanoparticle-conjugated conducting polymer nanocomposites

M Faisal et al. Front Chem. .

Abstract

An electrochemical nitrite sensor probe is introduced herein using a modified flat glassy carbon electrode (GCE) and SrTiO3 material doped with spherical-shaped gold nanoparticles (Au-NPs) and polypyrrole carbon (PPyC) at a pH of 7.0 in a phosphate buffer solution. The nanocomposites (NCs) containing Au-NPs, PPyC, and SrTiO3 were synthesized by ultrasonication, and their properties were thoroughly characterized through structural, elemental, optical, and morphological analyses with various conventional spectroscopic methods, such as field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller method. The peak currents due to nitrite oxidation were characterized in detail and analyzed using conventional cyclic voltammetry (CV) as well as differential pulse voltammetry (DPV) under ambient conditions. The sensor response increased significantly from 0.15 to 1.5 mM of nitrite ions, and the sensor was fabricated by coating a conducting agent (PEDOT:PSS) on the GCE to obtain the Au-NPs/PPyC/SrTiO3 NCs/PEDOT:PSS/GCE probe. The sensor's sensitivity was determined as 0.5 μA/μM∙cm2 from the ratio of the slope of the linear detection range by considering the active surface area (0.0316 cm2) of the flat GCE. In addition, the limit of detection was determined as 20.00 ± 1.00 µM, which was found to be satisfactory. The sensor's stability, pH optimization, and reliability were also evaluated in these analyses. Overall, the sensor results were found to be satisfactory. Real environmental samples were then analyzed to evaluate the sensor's reliability through DPV, and the results showed that the proposed novel electrochemical sensor holds great promise for mitigating water contamination in the real samples with the lab-made Au-NPs/PPyC/SrTiO3 NC. Thus, this study provides valuable insights for improving sensors for broad environmental monitoring applications using the electrochemical approach.

Keywords: Au-NPs/PPyC/SrTiO3 nanocomposites; differential pulse voltammetry; environmental remediation; glassy carbon electrode; nitrite detection.

PubMed Disclaimer

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Schematic representation of the fabricated nitrite sensor probe with a modified glassy carbon electrode (GCE) and Auto-Lab assembly operation.
FIGURE 2
FIGURE 2
FESEM and EDS analyses of the nanocomposites (NCs). Magnified images of the (A) pure SrTiO3, (B) PPyC, (C)/PPyC/SrTiO3, and (D) Au-NPs/PPyC/SrTiO3 NCs; (E) EDS image of the Au-NPs/PPyC/SrTiO3 NC and (F) elemental composition of Au-NPs/PPyC/SrTiO3 NC.
FIGURE 3
FIGURE 3
EDS mapping for elemental distribution in the Au-NPs/PPyC/SrTiO3 NC: (A) C, (B) O, (C) Ti, (D) N, (E) Au, and (F) Sr.
FIGURE 4
FIGURE 4
HRTEM analyses of the NCs. Magnified images of (A) pure SrTiO3, (B) PPyC, (C) PPyC/SrTiO3, and (D) Au-NPs/PPyC/SrTiO3 NCs; (E) lattice spacing and (F) selected-area electron diffraction pattern of the NC.
FIGURE 5
FIGURE 5
XPS results of the Au-NPs/PPyC/SrTiO3 NC: (A) Ti2p, (B) Au4f, (C) Sr3d, (D) O1s, (E) C1s, and (F) N1s.
FIGURE 6
FIGURE 6
(A) Phase crystallinity analysis of the Au-NPs/PPyC/SrTiO3 NC with comparison of its constituent elements and (B) surface area of the NC by BET analysis.
FIGURE 7
FIGURE 7
Electrochemical characterization of the Au-NPs/PPyC/SrTiO3 NC using cyclic voltammetry (CV): (A) investigation of the scan rate of the coated GCE using Au-NPs/PPyC/SrTiO3 NC in the oxidation reduction of 0.1 mM K4[Fe(CN)6]; (B) peak current versus square root of the SR for nitrite detection by CV with the Au-NPs/PPyC/SrTiO3 NC/GCE probe.
FIGURE 8
FIGURE 8
Nitrite is evaluated electrochemically through differential pulse voltammetry (DPV): (A) oxidation peak currents increased with concentration and (B) calibration curves of the nitrite sensor (current vs. concentration).
FIGURE 9
FIGURE 9
pH optimization in nitrite detection with the Au-NPs/PPyC/SrTiO3 NC/PEDOT:PSS fabricated GCE probe: (A) controlled experiment, (B) CV analysis of nitrite based on pH of the buffer, (C) bar diagram, and (D) stability performance of the working electrode.
FIGURE 10
FIGURE 10
Electrochemical investigation of 750.0 µM nitrite in the presence of other analytes by the CV technique.
SCHEME 1
SCHEME 1
Schematic representation of the detection mechanism of nitrite with the Au-NPs/PPyC/SrTiO3 NC/PEDOT:PSS fabricated GCE: (A) electrochemical oxidation of nitrite (NO2 −) on the fabricated electrode and (B) conversion of NO2 − to NO3 − depending on the injected concentration in the electrochemical cell.
See this image and copyright information in PMC

References

    1. Alam M. M., Asiri A. M., Hasnat M. A., Rahman M. M. (2022). Detection of L-aspartic acid with Ag-doped ZnO nanosheets using differential pulse voltammetry. Biosensors 12, 379. 10.3390/bios12060379 - DOI - PMC - PubMed
    1. Amini N., Maleki A., Maleki P. (2021). Electrochemical detection of nitrate ions via reduction of NO2− and oxidation of NO reactions based on Cu@TiO2 coreshell/nafion/polyalizarin immobilized electrode. Mater. Chem. Phys. 264, 124384. 10.1016/j.matchemphys.2021.124384 - DOI
    1. Asiri A. M., Adeosun W. A., Rahman M. M. (2020). Development of highly efficient non-enzymatic nitrite sensor using La2CuO4 nanoparticles. Microchem. J. 159, 105527. 10.1016/j.microc.2020.105527 - DOI
    1. Atuchin V. V., Kesler V. G., Zaitsev A. I., Molokeev M. S., Aleksandrovsky A. S., Kuzubov A. A., et al. (2013). Electronic structure of α-SrB4O7: experiment and theory. J. Phys. Condens. Matter. 25, 085503. 10.1088/0953-8984/25/8/085503 - DOI - PubMed
    1. Bahadoran Z., Mirmiran P., Jeddi S., Azizi F., Ghasemi A., Hadaegh F. (2016). Nitrate and nitrite content of vegetables, fruits, grains, legumes, dairy products, meats and processed meats. J. Food Compos. Anal. 51, 93–105. 10.1016/j.jfca.2016.06.006 - DOI

LinkOut - more resources