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It this paper, the comprehensive design process was carried out to fabricate selective, molecularly imprinted polymer (MIP). The material was used as a sorbent in the optimized analytical method, aimed at verifying the hypothesis that the conditions of an analytical process could convert 4-hydroxyphenylacetic acid to 4-hydro-3-nitrophenylacetic acid, comprising a series of novel studies. The design stage consisted of the analysis of specificity of the MIP, synthesized from the cross-linker and used five various functional monomers independently, in the presence of four different templates. The MIP from 1-vinylimidazole, imprinted by 4-hydroxyphenylacetic acid, revealed the highest specificity in relation to 4-hydro-3-nitrophenylacetic acid, with an affinity factor equal to 3, and the highest selectivity from a group of structurally similar and biologically important biomolecules. The theoretical analysis revealed that electrostatic interaction between the analyte and the polymer matrix enhanced selectivity. The physicochemical characterization showed the specific surface area of the MIP as being equal to 368.6 m2 g−1, and the presence of nitrogen atoms at the level of 6.80% wt., confirming the monomer residue in the material structure. The MIP was applied in the solid phase extraction protocol, allowing for the analysis of 4-hydroxy-3-nitrophenylacetic acid in a human urine sample. Finally, the conversion of 4-hydroxyphenylacetic acid in human urine in nitrate and nitrite salts at low pH conditions revealed an almost twofold increase in 4-hydro-3-nitrophenylacetic acid to 775 ± 81 ng L−1. The results also confirmed the applicability of the new MIP sorbent for the purpose of analysis of low levels of analyte, present in the complex sample.

The paper describes the formation of six aromatic N-(2-arylethyl)-2-methylprop-2-enamides with various substituents in benzene ring, viz., 4-F, 4-Cl, 2,4-Cl2, 4-Br, 4-OMe, and 3,4-(OMe)2 from 2-arylethylamines and methacryloyl chloride in ethylene dichloride with high yields (46–94%). The structure of the compounds was confirmed by 1H NMR, 13C NMR, IR, and HR-MS. Those compounds were obtained to serve as functionalized templates for the fabrication of molecularly imprinted polymers followed by the hydrolysis of an amide linkage. In an exemplary experiment, the imprinted polymer was produced from N-(2-(4-bromophenyl)ethyl)-2-methylprop-2-enamide and divinylbenzene, acting as cross-linker. The hydrolysis of 2-(4-bromophenyl)ethyl residue proceeded and the characterization of material including SEM, EDS, 13C CP MAS NMR, and BET on various steps of preparation was carried out. The adsorption studies proved that there was a high affinity towards the target biomolecules tyramine and L-norepinephrine, with imprinting factors equal to 2.47 and 2.50, respectively, when compared to non-imprinted polymer synthesized from methacrylic acid and divinylbenzene only.

Samples with complex matrix analyzed during explanation of pathogenesis of various diseases and food or environmental monitoring request advanced analytical and instrumental devices. Among the materials used for described purposes, quantum (QDs) or carbon dots (CDs) layered by molecularly imprinted polymer (MIP) shells have gained widespread attention. Unique optical and physicochemical properties of QDs/CDs together with high MIPs selectivity make the QD/CD-MIP conjugates capable of adsorbing specific target molecules – such a binding event is then transduced as the optical signal of the response by the QDs/CDs. This review includes brief introduction on principles of imprinting process, QD/CD properties and QD/CD-MIP preparation techniques. Then, recent advancement of QD/CD-MIP in bioanalysis including environmental, biological and food samples investigations are summarized and emphasized. Finally, current limits of QD/CD-MIPs are defined and prospects are outlined to intensify the capability of QD/CD-MIP in future bioanalytical procedures.

In this paper, we developed and validated a new analytical method to determine the pharmacokinetic profile of hordenine in plasma samples of human volunteers after oral administration of hordenine-rich dietary supplements. For this purpose, a magnetic molecularly imprinted sorbent was fabricated and characterized. The application of a magnetic susceptible material facilitates pretreatment step while working with a highly complex sample, reducing time and costs. An optimized, fast, and reliable separation step was combined with liquid chromatography tandem mass spectrometry, providing an analytical method for analysis of hordenine in human plasma after dietary supplement intake. The method was validated (lower limit of quantification of 0.05 μg/L), enabling the pharmacokinetic profile of hordenine to be determined. The highest concentration of hordenine was noted after 65 ± 14 min, reaching the value of 16.4 ± 7.8 μg/L. The average t1/2 was 54 ± 19 min. The apparent volume of distribution was 6000 ± 2600 L (66 ± 24 L/kg when adjusted for weight).

The objective of this study was to explore the role of enantiomers in the surface modification and adsorption process of polymers imprinted by chiral molecules. Here, R-, S- and R/S-1-aminoindanes (TR, TS and TR/S) were used as the model template molecules. Optimization of synthetic protocols facilitated preselection of the most efficient composition for a molecularly imprinted polymer (MIP)—methacrylic acid-co-ethylene glycol dimethacrylate—with satisfactory specificity and an imprinting factor equal to 3. This polymer composition was used further to analyse the effect of configuration of the template on adsorption properties. The results showed preferable adsorption of R-enantiomer, TR in the R-MIP and S-enantiomer, TS in the S-MIP but revealed variations in the binding capacities of TR and TS in the R- and S-cavity (stereoselectivity factor; k = 1.66 to 1.22, respectively). The theoretically analysed binding energies (ΔEB) of both TR and TS in the R-cavity (ΔEB = − 506.14 to − 256.77 kcal mol−1) and S-cavity (ΔEB = − 302.42 to − 347.18 kcal mol−1) were in agreement with empirical data. Morphology and porosity analyses revealed the impact of the template molecule on the pore system of the MIP and control (a non-imprinted polymer), but enantiomers were only found to have a negligible role. Binding characterization revealed that the physisorption-governed adsorption process and Dubinin–Radushkevich model fitted the experimental data best. Finally, terahertz spectroscopy was employed to confirm the similarity between both materials imprinted by each enantiomer.

In this paper, magnetic molecularly imprinted nano-conjugates were synthesized to serve as selective sorbents in a model study of tyramine determination in craft beer samples. The molecularly imprinted sorbent was characterized in terms of morphology, structure, and composition. The magnetic dispersive solid phase extraction protocol was developed and combined with liquid chromatography coupled with mass spectrometry to determine tyramine. Ten samples of craft beers were analyzed using a validated method, revealing tyramine concentrations in the range between 0.303 and 126.5 mg L−1. Tyramine limits of detection and quantification were 0.033 mg L−1 and 0.075 mg L−1, respectively. Therefore, the fabricated molecularly imprinted magnetic nano-conjugates with a fast magnetic responsivity and desirable adsorption performance could be an effective tool for monitoring tyramine levels in beverages.

Carbon dots, a kind of materials discovered nearly two decades ago, have attracted attention due to unique properties such as bright fluorescence emission, facile synthetic ways, high chemical and photostability, low cytotoxicity, good biocompatibility and environmental friendliness. The tunable fluorescence features caused widespread applicability in different scientific fields but mainly in biomedicine. However, the analytical methods that based on carbon dot fluorescence measurements are characterized by insufficient selectivity, weak anti-interference ability and moderate sensitivity. Thus, prior to utilization to highly complex biomedical samples, those materials have to be functionalized. Here, molecularly imprinted polymers are the class of materials, synthesized in the presence of template molecules, that provide sufficient selectivity, high cleanup capabilities as well as satisfactory enrichment potential. In this chapter, the biomedical application of molecularly imprinted polymer-functionalized carbon dots will be presented. The brief characterization of carbon dot synthetic approaches together with summarized overview of imprinting process and its limitations followed by detailed discussion of the current state of the art of the carbon dot molecularly imprinted polymer conjugates for biomedicine will provide insight into the future prospects of those advanced materials.

In the last 10 years, we have witnessed an extensive development of instrumental techniques in analytical methods for determination of various molecules and ions at very low concentrations. Nevertheless, the presence of interfering components of complex samples hampered the applicability of new analytical strategies. Thus, additional sample pre-treatment steps were proposed to overcome the problem. Solid sorbents were used for clean-up samples but insufficient selectivity of commercial materials limited their utility. Here, the application of molecularly imprinted polymers (MIPs) or ion-imprinted polymers (IIPs) in the separation processes have recently attracted attention due to their many advantages, such as high selectivity, robustness, and low costs of the fabrication process. Bulk or monoliths, microspheres and core-shell materials, magnetically susceptible and stir-bar imprinted materials are applicable to different modes of solid-phase extraction to determine target analytes and ions in a very complex environment such as blood, urine, soil, or food. The capability to perform a specific separation of enantiomers is a substantial advantage in clinical analysis. The ion-imprinted sorbents gained interest in trace analysis of pollutants in environmental samples. In this review, the current synthetic approaches for the preparation of MIPs and IIPs are comprehensively discussed together with a detailed characterization of respective materials. Furthermore, the use of sorbents in environmental, food, and biomedical analyses will be emphasized to point out current limits and highlight the future prospects for further development in the field.

The objective of this paper was to extend comprehensive theoretical and experimental investigations at the molecular level to identify factors responsible for the high selectivity of imprinted sorbents. This knowledge was utilized in a new analytical strategy devoted to the analysis of hordenine in human urine after beer consumption. Among the various polymeric compositions tested, the most effective material was built up from methacrylic acid and ethylene glycol dimethacrylate (MIP1), showing a satisfactory binding capacity (4.44 ± 0.15 µmol g−1) and high specificity towards hordenine (AF = 5.90). The comprehensive analyses of porosity data and surface measurements revealed differences between imprinted polymers. The characterization of binding sites of MIP1 revealed a heterogeneous population with two values of Kd (2.75 and 370 μmol L−1) and two values of Bmax (1.82 and 99 μmol g−1) for higher and lower affinity respectively. The extensive theoretical analyses of interactions between various analytes and the MIP model cavity showed the highest binding energy for hordenine (ΔEB1 = −175.17 kcal mol−1). The method was validated for selectivity, lowest limit of quantification, calibration curve performance, precision, accuracy, matrix effect, carry-over and stability in urine. Extracts were prepared according to guidelines of the European Medicines Agency. The validation criteria were fulfilled, and the method was satisfactorily applied to urine samples collected prior to, and 2 h after, consumption of 2 L of beer, revealing the presence of hordenine at the mean level of 129 ± 27 ng mL−1. Additionally, ability of the sorbent to purify the urine sample was assessed using flow injection analysis tandem mass spectrometry, for comparison with other extraction techniques.

Quantum dots (QDs) are attractive semiconductor fluorescent nanomaterials with remarkable optical and electrical properties. The broad absorption spectra and high stability of QD transducers are advantageous for sensing and bioimaging. Molecular imprinting is a technique for manufacturing synthetic polymeric materials with a high recognition ability towards a target analyte. The high selectivity of the molecularly imprinted polymers (MIPs) is a result of the fabrication process based on the template-tailored polymerization of functional monomers. The three-dimensional cavities formed in the polymer network can serve as the recognition elements of sensors because of their specificity and stability. Appending specific molecularly imprinted layers to QDs is a promising strategy to enhance the stability, sensitivity, and selective fluorescence response of the resulting sensors. By merging the benefits of MIPs and QDs, inventive optical sensors are constructed. In this review, the recent synthetic strategies used for the fabrication of QD nanocrystals emphasizing various approaches to effective functionalization in aqueous environments are discussed followed by a detailed presentation of current advances in QD conjugated MIPs (MIP-QDs). Frontiers in manufacturing of specific imprinted layers of these nanomaterials are presented and factors affecting the specific behaviour of an MIP shell are identified. Finally, current limitations of MIP-QDs are defined and prospects are outlined to amplify the capability of MIP-QDs in future sensing.

The aim of this study was to develop magnetic molecularly imprinted nano-conjugate sorbent for effective dispersive solid phase extraction of antazoline (ANT) and its metabolite, hydroxyantazoline (ANT-OH) in analytical method employing liquid chromatography coupled with mass spectrometry method. The core–shell material was characterized in terms of adsorption properties, morphology and structure. The heterogeneous population of adsorption sites towards ANT-OH was characterized by two Kd and two Bmax values: Kd (1) = 0.319 µg L−1 and Bmax (1) = 0.240 μg g−1, and Kd (2) = 34.6 µg L−1 and Bmax (2) = 5.82 μg g−1. The elemental composition of magnetic sorbent was as follows: 17.55, 37.33, 9.14, 34.94 wt% for Si, C, Fe and O, respectively. The extraction protocol was optimized, and the obtained results were explained using theoretical analysis. Finally, the analytical method was validated prior to application to pharmacokinetic study in which the ANT was administrated intravenously to three healthy volunteers. The results prove that the novel sorbent could be useful in extraction of ANT and ANT-OH from human plasma and that the analytical strategy could be a versatile tool to explain a potential and pharmacological activity of ANT and ANT-OH.

In this paper, we present an analysis of the surface modifications responsible for the selectivity of a new imprinted sorbent produced for the isolation of pentamidine cations. We examined the polymers formed from acrylic acid as the monomer, ethylene glycol dimethacrylate as the cross-linker and 4-methoxybenzamidine as the template. A molecular simulation showed the creation of the complex surface system joined with the protonation of the template molecule in a prepolymerization complex. Polymer cavity models enabled the adsorption process to be theoretically simulated, and the binding energies of the structurally related analytes were used as a measure of sorbent selectivity. An applicative analytical scheme for the determination of pentamidine in human urine was used to prove the utility of the templated polymer matrix. The analytical strategy involved separating the pentamidine through a molecularly imprinted solid phase extraction process and detecting it using high-performance liquid chromatography coupled with ultra-violet spectrophotometry. The experimental results demonstrated a good agreement with the theoretical evaluations.

A use of molecularly imprinted polymers (MIPs) in analytical proceedings has received much attention due to its advantages, such as high selectivity, robustness, and low preparation costs. Micro- and nanospherical MIPs possess better adsorption capability than traditional forms because of high surface to volume ratio and small size. It could be useful in the analytical methods. Thus, the combination of MIPs with nanomaterials possessing additional features, such as magnetic properties has been intensively explored. The advantages are analysis faster, easier and more effective analysis while complex biological samples are used. Magnetic molecularly imprinted polymers (MMIPs) provide a powerful analytical tool with wide-range potential in detection and quantification of analytes. This chapter will focus on diverse synthetic approaches for MMIPs emphasizing different properties of imprinted layer. The physicochemical behavior of MMIPs will be discussed in context of their practical utility. Analytical applications in various fields such as food chemistry and biomedical sciences will be highlighted. Finally, the current limits and future prospects for the MMIPs will be pointed out.

In this paper, poly(methacrylic acid-co-trimethylolpropane trimethacrylate) imprinted sorbent was constructed from equimolar amounts of cross-linker and selected ethylammonium methacrylates which were synthesized from respective ethylamines with very good yields (80–97%) prior to polymerization. The structure of resulted polymers was characterized by spectroscopy and thermogravimetry and the morphology was examined by scanning electron microscopy and porosity analyses. The adsorption behavior of obtained materials was evaluated towards various biogenic amines revealing significant difference in the binding capacities notably between tryptamine and norepinephrine (43.1 ± 5.2 to 14.3 ± 1.7 μmol g−1 and 20.2 ± 1.8 to 7.79 ± 0.68 μmol g−1 on MIP and NIP, respectively). Strong electrostatic interactions between analytes and MIPs could be recognized as the main forces responsible for adsorption but the effect of ethylammonium methacrylate was less expressive. Poly(methacrylic acid-co-trimethylolpropane trimethacrylate) prepared from 2-phenylethylammonium methacrylate was characterized by the highest affinity towards model biogenic amine, dopamine (AF = 3.04) with heterogeneous population of binding sites. The analysis of the separation of dopamine from spiked artificial urine sample revealed its high binding capacity (46.9 ± 1.3 μg g−1) and satisfactory total recovery (76.6 ± 2.8%).

Synthetic polymers possessing cavities designed for a target analyte (named molecularly imprinted polymers, MIPs) are used for the development of various analytical procedures. MIPs are used in the different steps of the methods including extraction and cleanup of analytes, as well as analysis of matrix effects. Basically, the analytes adsorbed by appropriate imprinted polymers in off-line or in on-line systems are eluted and detected directly using different analytical techniques or in combination with other separation techniques or sensors. Many procedures dealing with MIPs have been successfully elaborated and extensively reviewed. This chapter focuses on the commercially available MIP sorbents and the patented MIPs dedicated to the determination of pharmaceuticals. Additionally, some details of analytical procedures are presented for the isolation of pharmaceuticals from complex matrices.

Ten molecularly imprinted polymers coded as MIP1-MIP10 were prepared by the radical bulk polymerization using (R,S)-(±)-2-amino-1-phenylethanol as the structural analog of the target analyte (R,S)-octopamine. The functional monomers, 4-vinylbenzoic acid (1), methacrylic acid (2), acrylic acid (3), trifluoromethacrylic acid (4), itaconic acid (5), acrylamide (6), isopropenylbenzene (7), 2-hydroxyethyl methacrylate (8), 2-(diethylamino)ethyl methacrylate (9), allylamine (10) were polymerized consecutively with the ethylene glycol dimethacrylate cross-linker in methanol as the porogen. On the basis of the binding capacity of (R,S)-octopamine MIP1 with affinity factor equal to 6.37 was selected for further analysis. The affinity of polymer matrix MIP1 was tested by the non-competitive binding experiments of eight structurally related analytes. Finally, molecularly imprinted solid phase extraction (MISPE) of (R,S)-octopamine from spiked human serum albumin was carried out in order to verify the applicability of novel sorbent. The molecular modeling was employed to rationalize the stereodifferentiation of the analytes by the stereospecific sites formed in the polymer matrix.

Molecular imprinting is a technology for the synthesis of tailor-made recognition materials by polymerization of suitable functional monomers in the presence of desired template. As a result, smart polymers with high specificity and selectivity are obtained. Hydrogels are defined as insoluble polymeric networks produced from hydrophilic polymer chains with capability to absorb water and preserve their shape without dissolving. The imprinting of hydrogels is more complicated comparing to rigid structure. However, the exponential increase in fabrication of imprinted hydrogels is observed. The novel, advanced applications in pharmacy and medicine are explored including areas such as drug delivery systems or sensors in different analytical methods utilized in diagnostics. In this chapter, a brief overview of hydrogel imprinting process together with various synthetic approaches is discussed followed by detailed description of possible applications of imprinted hydrogels in pharmaceutical and biomedical sciences. Finally, some current limits and future prospects for the imprinted hydrogels are pointed out.

A 2-(4-methoxyphenyl)ethylamine imprinted polymer (MIP) was successfully applied for the selective separation of tyramine. A computational analysis was used to predict the affinity of the polymer matrix towards tyramine and a preliminary experimental evaluation was made for the target analyte. Then the experimental analysis of polymer towards tyramine was continued. The binding sites were characterized with employment of the Langmuir and Freudlich models. After the optimization of solid phase extraction towards tyramine, the most appropriate systems for the extraction steps were chosen: methanol-water 85:15 v/v for the loading and the washing as well as 0.04 M aq. ammonium acetate-methanol 30:70 v/v for the elution steps. The biogenic compounds as tryptamine, serotonin, octopamine, synephrine, and l-tyrosine were used for the selectivity study on the basis of binding capacities of the analytes on the imprinted and the non-imprinted polymers. The theoretical approach to obtained results allowed to explain the adsorption selectivity of the tested polymer. Finally, the complex matrix of bovine serum albumin was used to show the usefulness of imprinted material for bioanalysis. The obtained recoveries showed the superiority of MIP over the commercial sorbent C18. Total recoveries of tyramine from spiked bovine serum albumin sample were determined as: 95±2%, 14±3%, and 1.9±0.4% for the imprinted, non-imprinted, and commercial C18 sorbents, respectively.

The aim of this study was to create a new computational model capable of evaluating the affinity of imprinted materials to the specific target. A 1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone (L1), the main metabolite of voriconazole (L2)--a modern antifungal drug, was proposed as a template. In a computational analysis of polymerization systems composed of the template, the monomers and the cross-linker molecules the appropriate porogens were simulated. A non-covalent approach for the formation of a polymer matrix from eight functional monomers was employed in the theoretical and experimental studies. The binding affinities towards the template were measured for eight synthesized polymers. The experimental results confirmed that the proposed theoretical model properly showed isopropenylbenzene 1 as the most suitable monomer to synthesize the polymer with the best affinity to L1. The novel computational protocol was more suitable to predict the properties of polymer systems than the simple analysis of template-monomer interactions. On the basis of the polymerization complex P(MC1) (template-isopropenylbenzene 1-cross-linker), the adsorption cavity was modeled and the intermolecular interactions of the template molecule and the other voriconazole metabolites inside the cavity were analyzed to get an insight into the polymer matrix selectivity.