## 2 Molecular Imprinting by Surface Polymerization
Nevertheless, it is obvious that they can also be used for sensor development by nanoparticle auto-assembly [40]. In reference [56], a \"grafting from\" method is provided by [PERSON] and [PERSON], who reported water-compatible surface imprinting of \"baclofen\" on silica surface. As a supporting matrix, a silica gel was used and the synthesis of the MIP for a skeletal muscle relaxant, namely baclofen (4-amino-3-p-chlorophenylbutyric acid) was carried out on the surfaces of silica gel. An imprinting network of sulfobetaine polyelectrolyte was prepared in aqueous medium only. This was grafted onto the silica gel matrix using 3-aminopropylriethoxysilane (APTES) as a silane coupling agent and Michael addition reaction for further propagating the polymer grafting procedure. The rebinding studies showed that the MIP displayed good recognition for baclofen as compared to NIPs. Meanwhile, selectivity tests proved that MIP had a high affinity to baclofen in the presence of interferants (close structural analogues). Hence, a facile, specific, selective and water-compatible technique to detect baclofen in the presence of various interferants is provided. The prepared materials can be applied in HPLC as well as incapillary electrochromatography (CEC). An interesting \"dummy\" imprinting approach by surface polymerization is described by [PERSON] et al. [57]. In order to prepare sensitive layers for tricyclic antidepressants (TCAs) measurement in blood, the surface polymerization was performed on steel blades. In this respect, the pre-polymerization solution was obtained using a dummy template: benzyl(3-(10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl)propyl)(methyl) carbamate, MAA and EGDMA and cast on the steel blades. Subsequently, the photo initiator was added and the layers were covered with a glass cover. The idea of using a dummy template, in this case, was derived from the necessity to prevent template bleeding. For trace analysis, such as the one targeted in this work, the risk of false positive results can also be due to incomplete template removal. Thus, to avoid such issues a pseudo-template was employed. The prepared MIPs were used as sensitive layers for liquid chromatography in which case the adsorption efficiencies for the MIPs were 3 to 5 times better than for the non-imprinted analogous, confirming that the use of the pseudo-template led to improved performance in this case. The work of [PERSON] et al. [58] provides some insights regarding the surface molecular imprinting polymerization for obtaining a fluorescence sensor for the thermal and optical detection of nafcillin. The production of MIP films and particles was realized by integrating a fluorescent moiety that serves both as an element for template interaction and signaling. Fluorescein methacrylate (FluMa) was synthesized and introduced during the molecular imprinting process, first as the sole monomer and afterwards in an equimolecular mixture with MAA. The thin MIP films were deposited onto functionalized glass slides (to serve as electrodes) and the following UV-light initiated polymerization was performed in the presence of template species, nafcillin sodium salt.Although the specificity of films was not as high as that registered for the particles, the MIPs with FluMa and MAA were by far more performant than the ones with FluMa alone. Hence, the results are promising for developing a portable sensor for antibiotics [58].