## 2 Molecular Imprinting by Surface Polymerization
This polymer was cast on the gold working area of a screen-printed electrode (Au-SPE), creating in this manner a novel disposable device relying on plastic antibodies.The MIP/Au-SPE sensor displayed a linear behavior by electrochemical impedance spectroscopy (EIS) and a limit of detection set-out at 2.25 \(\mu\)g/mL. The MIP/Au-SPE sensor also displayed good results in terms of selectivity. The error found for each interfering species were 11% for BSA, 7% for troponin T and2% for creatine kinase MB, respectively. Overall, the MIP modification over the Au-SPE was found suitable for producing an electrochemical sensor for screening Myo in biological fluids [43]. One epitope approach by surface polymerization for MIP selective layers is also illustrated by [PERSON] and co-workers [44]. In the first step, the MIP was synthesized, using the epitope of human serum albumin as a template and afterwards, a coating method was applied to produce the quartz crystal microbalance sensor (EMIP-QCM). The MIP solution was prepared using zinc acrylateas a functional monomer, EGDMA as crosslinker and dimethylformamide (DMF) as porogen solvent. The gel precipitate was separated, washed and lyophilized. In order to obtain the sensor, a quartz crystal microbalance (QCM) crystal chip was used to drop-cast the MIP solution. The final MIP-QCM sensor displayed good selectivity and sensibility for human serum albumin, with a detection limit of 0.026 \(\mu\)g/mL. Furthermore, the sensor has also proven good accuracy and reproducibility when real samples were tested [45]. Further on, the study presented by [PERSON] and co-workers [46] is a typical example of a soft lithography approach and describes the design and synthesis of layer-by-layer MIPs via surface polymerization. The double-layered patterned MIP1/MIP2 was prepared on a silicon wafer. To enable chemical binding of MIP1 layer on the silicon, the surface of the wafer was first activated by sonication and exposed to UV-light, after which the surface was silanized with 3-(trimethoxysil)propyl methacrylate. The MIP pre-polymerization mixture was prepared by dissolving the template(\(N\)-dansyl-L-phenylalanine) and MAA with a crosslinker and a photo-initiator in a porogen solvent. This solution was spincoated onto the silanized silicon wafers and photo-polymerized. After template extraction, a 4-vinylpyridine-MIP thin film layer was deposited by photo-lithographic etching onto the first MIP film of PMAA, resulting in a grid-patterned surface in which two different MIPs, with pre-determined selectivity for \(N\)-dansyl-L-phenylalanine, alternated at a micron scale. Selectivity differences towards fluorescent template analogues were inspected using fluorescence microscopy [46]. MIP films can be prepared by surface polymerization also on organic support, such as multiwall carbon nanotubes (MWCNT) [47]. In this report, the used template was lysozyme (Lys) from egg white. The functional monomer was acrylamide (AAm), the crosslinker, methylene bis acrylamide (MBA) and the solvent, phosphate buffer (PBS). Besides using PBS for the protein protection, a redox initiation was employed consisting of ammonium persulfate (APS) and N,N,N\({}^{\prime}\),N\({}^{\prime}\)-tetramethylethylenediamine (TEMED), allowing to perform the surface polymerization at room temperature. The selectivity assays showed thatthe Lys-MIP film registered higher capacity and affinity for Lys than for the other competitive proteins, such as cytochrome C (Cyt C), myoglobin (Myo), hemoglobin (Hb) and bovine serum albumin (BSA). The relative selectivity coefficients for Lys/Cyt C, Lys/Myo, Lys/Hb, and Lys/BSA were 1.30, 1.30, 3.12 and 2.82, respectively, while the adsorption capacity of the Lys-MIP film was 1.86 times higher than that of the non-imprinted polymer (NIP). Although the material was intended for selective separation of lysozyme, it may also be of interest for sensor application as a result of excellent electric conductivity of MWNT [47].