Assessing the Food Quality Using Carbon Nanomaterial Based Electrodes by Voltammetric Techniques

Abstract

The world is facing a global financial loss and health effects due to food quality adulteration and contamination, which are seriously affecting human health. Synthetic colors, flavors, and preservatives are added to make food more attractive to consumers. Therefore, food safety has become one of the fundamental needs of mankind. Due to the importance of food safety, the world is in great need of developing desirable and accurate methods for determining the quality of food. In recent years, the electrochemical methods have become more popular, due to their simplicity, ease in handling, economics, and specificity in determining food safety. Common food contaminants, such as pesticides, additives, and animal drug residues, cause foods that are most vulnerable to contamination to undergo evaluation frequently. The present review article discusses the electrochemical detection of the above food contaminants using different carbon nanomaterials, such as carbon nanotubes (CNTs), graphene, ordered mesoporous carbon (OMC), carbon dots, boron doped diamond (BDD), and fullerenes. The voltammetric methods, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV), have been proven to be potential methods for determining food contaminants. The use of carbon-based electrodes has the added advantage of electrochemically sensing the food contaminants due to their excellent sensitivity, specificity, large surface area, high porosity, antifouling, and biocompatibility.

Keywords: cyclic voltammetry; differential pulse voltammetry; electrochemical sensors; food safety; graphene.

Figure 1

Types of carbon materials and the overview of the article.

Figure 2

(a) Schematic representation of an multi walled carbon nanotube (MWCNT)modified graphite electrode for tyrosine detection, (b) Cyclic voltammograms collected at 0.48 mM tyramine solution at a: Tyrosinase/TiO₂, b: Tyrosinase/TiO₂/polycationic polymer/Nafion, c: Tyrosinase/TiO₂/MWCNT/Nafion, and d: Tyrosinase/TiO₂/MWCNT/polycationic polymer/Nafion biosensors. Reprinted (adapted)with permission from Ref. [36]. Copyright 2016, Springer Nature.

Figure 3

Graphical representation of the whole experiment. Reprinted (adapted) with permission from Ref. [47]. Copyright 2021, Springer Nature.

Figure 4

(A) The cyclic voltammograms of bare glassy carbon electrode (GCE), 5-amino-1,3,4-thiadiazole-2-thiol-Pt/glassy carbon electrode (ATDT-Pt/GCE), and electrochemically reduced graphene oxide-5-amino-1,3,4-thiadiazole-2-thiol-Pt/glassy carbon electrode (ERGO-ATDT-Pt/GCE) in 50 µM at a scan rate of 100 mV/s; (B) the plot of redox peak current vs. scan rate in presence at 30–300 mV/s; (C) CV at different concentrations of the orange II dye (0, 2, 5, 10, 20, 30, 50, and 70 µM) Reprinted (adapted) with permission from Ref. [61]. Copyright 2015, Elsevier.

Figure 5

CV curve of catechol using a fabricated electrode at (a) 0.1 M PBS (pH 7) at the scan rate of 0.1 V/s. (b) Different scan rates from 0.1 to 0.3 V/s. (c) Different pH (6.5–8.0) with the sweep rate of 100 mV/s. Reprinted (adapted) with permission from Ref. [62]. Copyright 2020, Bentham Science.

Figure 6

Fabrication process of the modified electrode. Reprinted (adapted) with permission from Ref. [65]. Copyright 2017, Turkish Chemical Society.

Figure 7

Schematic representation of the silver nanoparticle/graphene nanoplatelets modified screen-printed carbon electrodes. Reprinted (adapted) with permission from Ref. [68]. Copyright 2021, American Chemical Society.

Figure 8

Graphical representation of preparing fluorescent carbon dots on a modified electrode to determine methylmercury. Reprinted (adapted) with permission from [72]. Copyright 2014, Elsevier.

Figure 9

CV curves of GCE (a,b), carbon dots/GCE (c,d) and carbob dots@Au/GCE (e,f) in the absence (a,c,e) and presence (b,d,f) of 0.2 mg/L ractopamine in a PBS (pH 7.0) solution. Reprinted (adapted) with permission from [76]. Copyright 2020, ESG.