## 2 Hybrid Graphene-Based Materials (Hybrid GBMs)
### Molecularly Imprinted Polymers  
MIPs represent a distinct category of materials primarily utilized as sorbent phases in various conventional and miniaturized sample preparation methodologies. These materials are designed to facilitate selective interactions between the sorbent and the target analyte, thereby potentially enhancing the efficiency and specificity of the method. The synthesis of MIPs predominantly involves three common approaches: (I) non-covalent technique, (II) covalent pre-organized approach, and (III) semi-covalent strategy [61]. Across these synthesis methodologies, the fundamental principle remains consistent: employing a template-based approach wherein a template molecule, typically representing the target analyte, is utilized to construct a three-dimensional polymeric structure. The obtained structure contains specific cavities molded by the presence of the template molecule. Subsequent template removal through a washing procedure renders these cavities available for particular interactions with the target analyte, which shares analogous physicochemical properties with the template. This enables effective recognition and separation within complex matrices [52; 61]. Given the inherent advantages of utilizing MIPs as sorbent phases, there has been a notable surge of interest in their combination with GBMs. [PERSON] et al. [36] demonstrated the synthesis of a novel poly(deep eutectic solvents) surface-imprinted graphene oxide composite (PDESs-MIP/GO). The synthesis involved several distinct steps. Initially, sulfhydryl-functionalized GO (SH-GO) was prepared by adding (3-mercaptoethanolopropyl)trimethoxysilane to a GO dispersion. Subsequently, two DESs were synthesized. The first DES (DES 1), intended as the monomer for the final MIP, was created by mixing allyl trimethylammonium chloride and urea. The second DES (DES 2), used as the crosslinker, was synthesized by combining allyl trimethylammonium chloride and itaconic acid. The final PDESs-MIP/GO sorbent was formed using SH-GO as the carrier, DES 1 as the functional monomer, DES 2 as the crosslinker, and epinephrine as the template molecule. The resultant polymer exhibited a remarkable imprinting factor (-2.0), primarily attributed to the choice of starting materials. Moreover, this study highlights the potential of DESs in providing an eco-friendly alternative for synthesizing MIPs based on graphene oxide, effectively circumventing the use of traditional and harmful organic solvents typically employed in conventional MIP synthesis procedures. Another modification of GO with MIP was proposed by [PERSON] et al. [38]. In this study, the authors first modified GO using a polymerizable silane group to create reactive sites for polymer grafting. For the MIP synthesis, the molecularly imprinted polymer-graphene oxide (MIP-GO) was immersed in a solution containing triphenyl phosphate (TPhP) as the template molecule, acrylamide (AM), ethylene glycol dimethacrylate (EGDMA), and azobisisobutyronitrile (AlBN). Fibers were also prepared without the addition of GO. The main results demonstrated that the incorporation of GO significantly improved the physicochemical properties of the polymer, such as specific surface area and adsorption capability, highlighting the importance of including this graphene-based material to improve analytical aspects of MIP applications. [PERSON] et al. [39] proposed a similar MIP-GO using different organophosphate flame retardants (OPFRs) as the template molecules to evaluate their analytical performance. Among the synthesized polymers, the one with TPhP exhibited the highest imprinting factor value (10.3). Despite this, the authors introduced an innovative strategy by assembling the three synthesized fibers into a 250 \(\upmu\)m o.d. array called the GO-based surface molecularly imprinted polymeric fiber array (GO/MIP-FA). This strategy demonstrated superior analytical performance compared to traditional fibers such as polydimethylsiloxane (PDMS) (100 \(\upmu\)m o.d.) and polyacrylate (PA) (80 \(\upmu\)m o.d.).