# Functionalized Carbon-Based Electrochemical Sensors for Food and Alcoholic Beverages Safety
## 3 Carbon Nanomaterial-Based Electrochemical Sensors
### Graphene
\begin{tabular}{c c c c c c c} \hline \hline
**Analytes** & **Materials** &
\begin{tabular}{c} **Electrochemical** \\ **Techniques** \\ \end{tabular} & **Linear Range** & **Detection Limit** & **Sample** & **Ref.** \\ \hline Atropine & Graphene-PLA & SWV & 5–60 uM & 1 uM & Wines & [99] \\ Amino acids & Nanographene & CA & LR\({}_{\text{n}}\), LR\({}_{\text{i}}\), LR\({}_{\text{o}}\), & DL\({}_{\text{n}}\), DL\({}_{\text{d}}\), DL\({}_{\text{o}}\), & Wines & [100] \\ Gallic acid & CS–free\({}_{\text{n}}\)O\({}_{\text{i}}\)–ERGO & DPV & 1–100 uM & 0.15 uM & Wines & [101] \\ Aflatoxin B1 & FGO & CV and PDV and & 0.05–6.0 ng mL\({}^{-1}\) & 0.05 ng mL\({}^{-1}\) & Wines & [102] \\ Aflatoxin B1 & RGO/MoS\({}_{\text{2}}\)/PANI@Au/Cs & DPV & 0.01–1.0 fg mL\({}^{-1}\) & 0.002 fg mL\({}^{-1}\) & Wines & [103] \\ Saccharomyces cerevisiae & PA-GO/SPE & CA & 10–107 CFU & ND & White wine & [104] \\ _trans_-Resveratrol & LPG & CV and DPV & 0.2–50 uM & 0.16 uM & Red wine & [105] \\ _trans_-Resveratrol & Gr-MoS\({}_{\text{2}}\) & DPV & 1.0–200 uM & 0.45 uM & Red wine & [106] \\ Caffe acid & SnO\({}_{\text{2}}\)-RGO & DPV & 0.15–25 uM & 80 nM & Red wine & [107] \\ Fe\({}^{\text{3+}}\) & po-Gr-NR & CV and DPV & 37.5 nM\({}_{\text{2}}\)-21.53 & 18.7 nM & Red wine & [108] \\ Sunset yellow and & & & & & & \\ Tartrazine & GN/TiO\({}_{\text{2}}\) & CV and SWV & LR\({}_{\text{g}}\), LR\({}_{\text{nt}}\) & DL\({}_{\text{sy}}\), DL\({}_{\text{nt}}\) & Foods & [109] \\ Bisphenol A & GNPs/GR & CV & 0.01 uM–10 uM & 5 nM & Milk & [110] \\ TRA & GCE1/Gr-Au/MIP* & CV & 0.01–10 uM & 0.0044 uM & Foods and & [111] \\ Vitamin C & Au NPs/PCA-RGO & CV & 50–500 uM & 17 uM & Foods & [112] \\ Aflatoxin B1 & AuNPs/FOO/ITO & CV & Nr & 6.9 fg mL\({}^{-1}\) & Foods & [113] \\ \hline \hline \end{tabular}   
* PLa: polyactic; CV: cyclic voltammetry; CA: chronoamperometry; DPV: differential pulse voltammetry; SWV: square wave voltammetry; ESI: electrochemical impedance spectroscopy; mM: millimolar; uM: micromolar; nM: nanomolar; pg; picogram; fg: femtogram; CS: chitosan; Fe\({}_{\text{3}}\)O\({}_{\text{4}}\): ferroferroic oxide; ERGO: electrochemically reduced graphene oxide; FGO: functional graphene oxide; ROO: reduced graphene oxide; MoS\({}_{\text{2}}\): molybdenum disulfide; PANI: polyaniline; AuNPs: gold nanoparticles; PA-GO: propionate acid–functionalized graphene oxide; LPG: laser-induced porous graphene; po-Gr-NR: NRC-rated partially oxidized graphene; CCE: glassy carbon electrode; MIP: molecularly imprinted polymer; PCA: 1-pyrene carboxylic acid; LR\({}_{\text{n}}\):0.1 nM–0.1 uM; LR\({}_{\text{n}}\): 0.1–100 uM; LR\({}_{\text{6}}\): 0.1 nM–10 nM; DL\({}_{\text{n}}\): 0.1 nM; DL\({}_{\text{4}}\): 0.1 nM; DL\({}_{\text{o}}\): 10 nM; DL\({}_{\text{e}}\): 0.1 nM; LR\({}_{\text{g}}\): 0.02–2.05 uM; LR\({}_{\text{nt}}\): 0.02–1.18 uM; DL\({}_{\text{electrochemical catalysis field [114]. Identification and detection of iron (III) (ferriciron, Fe\({}^{3+}\)) are challenging in the complex system using traditional detection techniques. As shown in Figure 5c, the Fe\({}^{3+}\) electrochemical sensor was constructed by depositing the partially oxidized graphene sheets (po-Gr) on a glassy carbon electrode. The linear response range and the limit of detection of Fe\({}^{3+}\) were obtained from 37.5 nM to 21.53 mM and 18.7 nM in the presence of other valence ions, such as Fe\({}^{2+}\), Cu\({}^{2+}\), Pb\({}^{2+}\), Hg\({}^{2+}\), Mn\({}^{2+}\), Ni\({}^{2+}\), Zn\({}^{2+}\), Co\({}^{2+}\), and Cd\({}^{2+}\), respectively. Interestingly, in this work, partially oxidized graphene sheets provided active sites for selectively capturing Fe\({}^{3+}\), allowing it to be detected in low concentrations in complex red wine samples [108]. Metal oxides are stable heterogeneous catalysts with abundantly exposed active sites, and have been extensively studied in photocatalytic, electrochemical, and traditional thermal catalytic reactions.