## 2 Molecular Imprinting by Surface Polymerization
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Synthesis Method** & **Receptor** & **Support** & **Analyte** & \begin{tabular}{c} **Characterization** \\ **Method(s)** \\ \end{tabular} & **LOD** & **Refs.** \\ \hline \multirow{2}{*}{\begin{tabular}{c} Spincoating \\ MIP nanoparticles \\ \end{tabular} } & MIP film & \multirow{2}{*}{Glass} & \multirow{2}{*}{Atrazine} & RIFs [1] measurements. & \multirow{2}{*}{\(>\)1.7 ppm} & [40] \\ \hline \multirow{2}{*}{\begin{tabular}{c} Precipitation \\ polymerization/polymer casting \\ \end{tabular} } & \multirow{2}{*}{MIP layer} & \multirow{2}{*}{SERS substrate [2]} & Enrofloxacin & \multirow{2}{*}{Raman} & \multirow{2}{*}{\(10^{-7}\) mol-L\({}^{-1}\)} & [41] \\  & & & & & & \\ \hline \multirow{2}{*}{\begin{tabular}{c} Casting \\ \end{tabular} } & MIP membrane & \multirow{2}{*}{\begin{tabular}{c} Screen-printed \\ gold electrode \\ \end{tabular} } & \multirow{2}{*}{Myoglobin} & EIS [3] & \multirow{2}{*}{2.25 ug\(\cdot\)mL\({}^{-1}\)} & [42] \\  & & & & SWV [4] & & \\ \hline \multirow{2}{*}{\begin{tabular}{c} Grafting polymerization \\ synchronized \\ with crosslinking/ \\ imprinting \\ \end{tabular} } & \multirow{2}{*}{MIP film} & \multirow{2}{*}{GCE [5]} & \multirow{2}{*}{Olaquindox} & \multirow{2}{*}{CV [6], DPV [7], EIS} & \multirow{2}{*}{7.5 nmol L\({}^{-1}\)} & [43] \\ \hline \multirow{2}{*}{\begin{tabular}{c} Covalent imprinting/ \\ drop casting \\ \end{tabular} } & MIP film & \multirow{2}{*}{Au-TFME [8]} & \multirow{2}{*}{\begin{tabular}{c} SARS-CoV-2 spike \\ protein subunit S1 \\ \end{tabular} } & \multirow{2}{*}{CV, SWV} & \multirow{2}{*}{4.8 pg\(\cdot\)mL\({}^{-1}\)} & [44] \\  & & & & & \\ \hline \multirow{2}{*}{\begin{tabular}{c} Dropcasting \\ \end{tabular} } & MIP membrane & \multirow{2}{*}{QCM [9] crystal chip} & Human & \multirow{2}{*}{\
\begin{tabular}{c} Langmuir, Freundlich, \\ Langmuir-Freundlich \\ isotherm \\ \end{tabular} } & \multirow{2}{*}{0.026 ug mL\({}^{-1}\)} & [45] \\  & & & serum albumin & & \\ \hline \multirow{6}{*}{
\begin{tabular}{c} 1 RIFs: reflectometric interference spectroscopy; 2 SERS: surface-enhanced raman scattering; silver nanoparticles modified by 3-methacrylacrylpropyltrimethoxysilane; 3 EIS: electrochemical Impedance spectroscopy; 4 SWV: square wave voltammetry; 5 glassy carbon electrode; 6 cyclic voltammetry; 7 differental pulse voltammetry; 8 MicruX(tm) gold-based thin-film metal electrodes; 9 QCM: quartz crystal microbalance. \\ \end{tabular} } \\  & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: MIP-based sensors obtained by surface polymerization. Figure 3: The principle of MIP layer preparation by surface polymerization. Another optical sensor is described by [PERSON] et al. [40], in which case reflectometric interference spectroscopy (RIfS) was employed as a detection method, while the MIP films were prepared with the pesticide atrazine as the template molecule. In their study, the MIP films were deposited on glass transducers by two different methods: (i) spin-coating of pre-polymerization mixture containing polyvinyl acetate as a sacrificial polymeric porogen, followed by in situ surface polymerization of thin films, and (ii) auto-assembly of MIP nanoparticles with the aid of polyethylene imine (PEI) as an associative linear polymer. The results obtained upon assessment of atrazine solutions in toluene were reproducible for both types of films. However, the film prepared with auto-assembled MIP nanoparticles was more sensitive, tracking atrazine down to 1.7 ppm. An example of the template immobilization approach is given in reference [42], where [PERSON] et al. developed a reusable sensor for Myo based on an MIP, prepared by assembling a polymer layer of carboxylated poly(vinyl chloride) (PVC COOH).