# SPR-Optical Fiber-Molecularly Imprinted Polymer Sensor for the Detection of Furfural in Wine +
Footnote †: Supported by the National Natural Science Foundation of China under Grant No. 1131100007. [PERSON]  
1  
[PERSON]  
2 Department of Engineering, University of Campania [PERSON], Via Roma n.29, 81031 Aversa, Italy; [EMAIL_ADDRESS] (L.Z. ); [EMAIL_ADDRESS] (N.C.)  
[PERSON]  
3 Ricerca sul Sistema Energetico-RSE S.P.A.-Via R. Rubatting n.54, 20134 Milano, Italy; [EMAIL_ADDRESS]  
[PERSON]  
1  
[PERSON]  
2 Department of Engineering, University of Campania [PERSON], Via Roma n.29, 81031 Aversa, Italy; [EMAIL_ADDRESS] (L.Z. ); [EMAIL_ADDRESS] (N.C.)  
[PERSON]  
3 Ricerca sul Sistema Energetico-RSE S.P.A.-Via R. Rubatting n.54, 20134 Milano, Italy; letizia.demaria@rese.weit  
[PERSON]  
1  
[PERSON]  
2 Department of Engineering, University of Campania [PERSON], Via Roma n.29, 81031 Aversa, Italy; [EMAIL_ADDRESS] (L.Z. ); [EMAIL_ADDRESS] (N.C.)  
Footnote 20: emailThe SPR-POF platform developed by our research group is particularly convenient for sensing purposes when it is combined with receptors, as molecularly imprinted polymers (MIP) [13]. It is based on the SPR phenomenon taking place at a multilayer structure realized starting from a planar surface of exposed core POF, embedded in a resin block (D-shaped POP platform). The receptor layer is deposited on the gold-photoresist multilayer [13]. The flat shape of the sensing part is particularly suitable for measurements in a drop, for which no expensive and bulky flow-through cell is required. The D-shaped POF sensing platform, developed by our research group, has been exploited in several application fields, employing different kinds of receptors, as aptamers, antibodies, metal ligands, and MIPs [13; 14; 15; 16; 17; 18; 19; 20]. The MIPs are a class of artificial receptors whose concept dates back to the early 1930s [21; 22; 23]. Peculiar is the process of MIP preparation, which is based on a template-assisted synthesis [24]. The target molecule is dissolved in a liquid phase together with functional monomers able to coordinate around it both by covalent or non-covalent bonds. Next, the complex is polymerized in the presence of a cross-linking agent. Upon template removal, cavities are left on the polymeric material; they are complementary to the template in shape, size, and position of recognition sites. MIPs often possess recognition properties analogous to natural receptors but have the stability, ease of preparation, micromachining, integrability, and low cost of production, typical of synthetic materials [24; 25; 26]. MIPs are synthetic solids containing sites functionally and dimensionally complementary to the target molecular structure, similar to the receptor sites in bioreceptors. Moreover, it is important to emphasize that MIPs can be produced as layers in tight contact with the transducing surfaces [13; 14]. It must be recognized that in this form, MIPs are different from the usual bioreceptors, for example, antibodies or aptamers, since their thickness can be higher than that of the bioreceptors' layers, usually constituted by only one or a few molecular layers. This aspect can be very important to reduce the so-called \"bulk effect\". In particular, the MIP's thickness can be modified in function of the real matrices in which the analyte is present; for instance, to exploit SPR-POF platforms to detect specific substances in power transformer oils, very thick MIP layers have been used [14]. MIPs have been found to have many interesting applications for selective separations and as biomimetic receptors in sensing devices, mainly for detection outside the laboratory, because of their robustness characteristics in different conditions (acidity, ionic strength, etc. ), low cost, and fast development. In the D-shaped SPR-POF platform proposed by us, an MIP layer can be easily deposited by a drop coating and spinning procedure, as previously described in several cases [13; 14; 19; 27].