## 5 Molecular Imprinting by Sol-Gel Derived Techniques
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **Deposition** & **Support** & **Analyte** & \begin{tabular}{c} **Characterization** \\ **Method(s)** \\ \end{tabular} & **LOD** & **Refs.** \\ \hline \multirow{9}{*}{\begin{tabular}{} \end{tabular} } & Spin coating & MIP film & Modified GCE [1] & Theophylline & CV [2] and DPASV [3] & 1.4 \(\times\) 10\({}^{-9}\) M & [146] \\  & Immersion & MIP film & \begin{tabular}{c} Modified \\ Au 4 electrode \\ \end{tabular} & Melamine & CV and SWV [5] & 0.4 \(\times\) 10\({}^{-9}\) M & [147] \\  & Spin coating & MIP film & \begin{tabular}{c} Au surface of \\ SPR device \\ \end{tabular} & Amoxicillin & SPR [6] and CV & 7.3 \(\times\) 10\({}^{-11}\) M & [148] \\  & Spin coating & MIP film & \begin{tabular}{c} Au modified \\ glass substrate \\ \end{tabular} & Cis-jsamone & FT-IR [7], LSPR [8] & 3.5 ppm & [149] \\  & Spin coating & MIP film & SPR substrate & Trinitotoluene & SPR & 0.26 ppb & [150] \\  & Immersion & MIP film & Modified GCE & Chlorogenic acid & DPV [9] & 3.2 \(\times\) 10\({}^{-8}\) M & [151] \\  & Dripping & MIP film & \begin{tabular}{c} SPE 10 \\ \end{tabular} & Europium & CV, EIS [11], DPV & 1 \(\times\) 10\({}^{-7}\) M & [152] \\  & Dripping & MIP film & GCE & Aspartic acid & SWSV [12] & 1.77 \(\times\) 10\({}^{-6}\) M & [153] \\  & Coating & MIP film & McNTs [13] & Aristolchic acid & Adsorption & 0.034 ug/mg & [154] \\  & Immersion & MIP film & GCE & Trichloron & EIS and CV & 2.8 \(\times\) 10\({}^{-9}\) g/mL & [155] \\  & Electrochemical & MIP film & Au electrode & Clenbuterol & DPV & 3.1 \(\times\) 10\({}^{-8}\) M & [156] \\  & Electrochemical & MIP film & GCE & Melamine & DPV & 6.8 \(\times\) 10\({}^{-8}\) M & [157] \\ Hybrid sol-gel & Electrochemical & MIP film & \
\begin{tabular}{c} Modified \\ ITO 14 electrode \\ \end{tabular} & Naloxone & CV and DPV & 2 \(\times\) 10\({}^{-8}\) M & [158] \\  & Electrochemical & MIP film &
\begin{tabular}{c} GCE \\ Modified GCE \\ \end{tabular} & Mephedrone & SWV & 8 \(\times\) 10\({}^{-10}\) M & [159] \\  & Electrochemical & MIP film & Modified GCE & Diethylstilbestol & DPV & 24.3 g/mL & [160] \\  & Electrochemical & MIP film & Pencil & Ketamine & EIS and SWV & 7 \(\times\) 10\({}^{-10}\) M & [161] \\ \hline \hline \end{tabular}  
* \({}^{1}\) GCE: glassy carbon electrode; \({}^{2}\) CV: cyclic voltammetry; \({}^{3}\) DPASV: differential pulse anodic stripping voltammetry; \({}^{4}\) Au electrode: gold electrode; \({}^{5}\) SWV: square wave voltammetry; \({}^{6}\) SPR: surface plasmon resonance; \({}^{7}\) FT-IR: Fourier transform-infrared spectroscopy; \({}^{8}\) LSPR: localized surface plasmon resonance; \({}^{9}\) DPV: differential pulse voltammetry; \({}^{10}\) SPE: screen-printed electrode; \({}^{11}\) EIS: electrochemical impedance spectroscopy; \({}^{12}\) SWSV: square wave stripping voltammetry; \({}^{13}\) MCNTs: magnetic carbon nanotubes; \({}^{14}\) ITO: indium tin oxide electrode.  
\end{table} 
Table 4: MIP-based sensors obtained by sol–gel method. the surface of the modified electrode by immersing the electrode in the MIP solution and rotating at 1500 rpm. In this case, the MIP solution was prepared by mixing TEOS, PTMOS and APTES in 2-ethoxyethanol, with the catalyst solution of HCl containing the template (chlorogenic acid). The detection limit of the prepared sensor was 0.032 uM, which was suitable for chlorogenic acid detection [151]. Considering the toxic effect of europium on human health, [PERSON] and co-workers [152] focused their interest on the development of a sensor for its detection. In this respect, they modified the surface of a SPE by electropolymerization using catechol, resulting in a poly (catechol) layer, after which the MIP layer was deposited. The precursor gel solution for the MIP was obtained by mixing TEOS, PTMOS and MTMOS with a solution of europium, in acidic conditions. The imprinted film was obtained by dripping the precursor solution on the modified electrode surface and dried at room temperature.