Sensitive Electrochemical Detection of 4-Nitrophenol with PEDOT:PSS Modified Pt NPs-Embedded PPy-CB@ZnO Nanocomposites

Mohd Faisal; Md Mahmud Alam; Jahir Ahmed; Abdullah M Asiri; Mohammed Jalalah; Raja Saad Alruwais; Mohammed M Rahman; Farid A Harraz

doi:10.3390/bios12110990

Sensitive Electrochemical Detection of 4-Nitrophenol with PEDOT:PSS Modified Pt NPs-Embedded PPy-CB@ZnO Nanocomposites

Biosensors (Basel). 2022 Nov 8;12(11):990. doi: 10.3390/bios12110990.

Authors

Mohd Faisal^{1

2}, Md Mahmud Alam³, Jahir Ahmed¹, Abdullah M Asiri^{3

4}, Mohammed Jalalah^{1

5}, Raja Saad Alruwais⁶, Mohammed M Rahman^{3

4}, Farid A Harraz^{1

7}

Affiliations

¹ Promising Centre for Sensors and Electronic Devices (PCSED), Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran 11001, Saudi Arabia.
² Department of Chemistry, Faculty of Science and Arts, Najran University, Najran 11001, Saudi Arabia.
³ Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University, Jeddah 21589, Saudi Arabia.
⁴ Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
⁵ Department of Electrical Engineering, College of Engineering, Najran University, Najran 11001, Saudi Arabia.
⁶ Chemistry Department, Faculty of Science and Humanities, Shaqra University, Dawadmi 17472, Saudi Arabia.
⁷ Department of Chemistry, Faculty of Science and Arts at Sharurah, Najran University, Najran 11001, Saudi Arabia.

Abstract

In this study, a selective 4-nitrophenol (4-NP) sensor was developed onto a glassy carbon electrode (GCE) as an electron-sensing substrate, which decorated with sol-gel, prepared Pt nanoparticles- (NPs) embedded polypyrole-carbon black (PPy-CB)/ZnO nanocomposites (NCs) using differential pulse voltammetry. Characterizations of the NCs were performed using Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS), Ultraviolet-visible Spectroscopy (UV-vis), Fourier Transform Infrared Spectroscopy (FTIR), High Resolution Transmission Electron Microscopy (HRTEM), and X-ray Diffraction Analysis (XRD). The GCE modified by conducting coating binders [poly(3,4-ethylenedioxythiophene) polystyrene sulfonate; PEDOT:PSS] based on Pt NPs/PPy-CB/ZnO NCs functioned as the working electrode and showed selectivity toward 4-NP in a phosphate buffer medium at pH 7.0. Our analysis of 4-NP showed the linearity from 1.5 to 40.5 µM, which was identified as the linear detection range (LDR). A current versus concentration plot was formed and showed a regression co-efficient R² of 0.9917, which can be expressed by i_p(µA) = 0.2493C(µM) + 15.694. The 4-NP sensor sensitivity was calculated using the slope of the LDR, considering the surface area of the GCE (0.0316 cm²). The sensitivity was calculated as 7.8892 µAµM^-1cm^-2. The LOD (limit of detection) of the 4-NP was calculated as 1.25 ± 0.06 µM, which was calculated from 3xSD/σ (SD: Standard deviation of blank response; σ: Slope of the calibration curve). Limit of quantification (LOQ) is also calculated as 3.79 µM from LOQ = 10xLOD/3.3. Sensor parameters such as reproducibility, response time, and analyzing stability were outstanding. Therefore, this novel approach can be broadly used to safely fabricate selective 4-NP sensors based on nanoparticle-decorated nanocomposite materials in environmental measurement.

Keywords: 4-nitrophenol detection; Pt-NPs-embedded PPy-CB/ZnO nanocomposites; differential pulse voltammetry; environmental safety; glassy carbon electrode.

MeSH terms

Carbon / chemistry
Electrodes
Limit of Detection
Nanoparticles* / chemistry
Reproducibility of Results
Soot
Zinc Oxide* / chemistry

Substances

poly(3,4-ethylene dioxythiophene)
4-nitrophenol
Zinc Oxide
Soot
Carbon

Grants and funding

NU/RG/SERC/11/18/Deanship of Scientiﬁc Research at Najran University