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A novel molecularly imprinted organic-inorganic hybrid composite material (MIP-HCM) was developed based on molecular imprinting technique in combination with hybrid composite synthesis and sol-gel technology for selective solid-phase extraction (SPE) of tetracyclines residues in milk. The MIP-HCM was prepared using oxytetracycline as the template,...
Citations
... The polymerization process to obtain MIP was evaluated by FT-IR analyses, with characteristic bands of the synthesized polymer [32,33] shifted or suppressed due to the reaction process (Fig. 1). The presence of poly(methacrylic acid) was confirmed in the frequency at 3452 cm −1 of OH group vibrations [32,34], in the -CH 2 and -CH 3 asymmetric stretching vibrations at 2989 and 2953 cm −1 [32,35], in the expressive band at 1725 cm −1 attributed to the C=O stretching and in the frequency at 1634 cm −1 , characteristic of the elongation of the C=O and C=C bonds of unreacted vinylic groups of methacrylic acid [36]. The band of the crosslinker used for preparing the MIP, ethylene glycol dimethacrylate, was observed at 1455 and 1386 cm −1 , respectively, regarding angular deformation of the -CH 2 and -CH 3 groups, and at (1) LD =ẍ bi + ks bi 1164 cm −1 attributed to the R-COO-R′ of the ester group [32,37]. ...
Atrazine (ATZ) is one of the most widely used triazine herbicides in the world; it is highly toxic and poses a risk to environmental balance and human health. Therefore, its detection and monitoring of allowed concentrations are vital, preferably using simple and relatively low-cost analytical methods. Molecularly imprinted polymers (MIPs) are synthetic structures containing imprinted nanocavities that can specifically bind to their target with high sensitivity, selectivity, and viability. In this work, MIPs were synthesized by the precipitation method, using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and atrazine as a template molecule in a single polymerization step, unlike other complex methodologies reported in the literature. For comparison purposes, NIP (non-imprinted polymer) was prepared. MIPs and NIPs were characterized using infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Through cyclic voltammetry (CV) and differential pulse (DP), atrazine was detected in an accurate spring water sample containing 1 to 100 ppb of the herbicide. The limit of detection (LOD) found was 0.02. Therefore, it was possible to synthesize an efficient MIP for detecting atrazine in spring water through a simple methodology.
... The functional monomer selection and its optimization are critical in the method because the adsorption and selectivity of the MIP depend entirely on it (Wong et al. 2016). Previous studies have demonstrated the effectiveness of methacrylic acid and divinylbenzene as monomers in the preparation of non-covalent MIPs (Lv et al. 2012;Yuan et al. 2011;Zhang et al. 2015). The polymer synthesis was carried out with slight modifications based on previous work conducted by our research group (de . ...
Water pollution is a current global concern caused by emerging pollutants like
nonylphenol (NP). This endocrine disruptor cannot be efficiently removed with
traditional wastewater treatment plants (WTP). Therefore, this work aimed to evaluate the adsorption influence of Molecularly Imprinted Polymers (MIPs) on the oxidative degradation (ozone and ultraviolet irradiations) of 4-Nonylphenol (4-NP) and its byproducts as a coadjuvant in WTP. MIPs were synthesized and characterized; the effect of the degradation rate under system operating conditions was studied by BoxBehnken response surface design of experiments. The variables evaluated were 4-NP concentration, ozone exposure time, pH, and MIP amount. Results show that the MIPs synthesized by co-precipitation and bulk polymerizations obtained the highest retention rates (>90%). The maximum adsorption capacities for 4-NP were 201.1 mg L-1 and 500 mg L-1, respectively. The degradation percentages under O3 and UV conditions reached 98-100 % at 120 seconds of exposure at the different pHs. The degradation products of 4-NP were compounds with carboxylic and ketonic acids, and the MIP adsorption was between 50 and 60%. Our results present the first application of MIPs in oxidation processes for 4-NP, representing starting points for the use of highly selective materials to identify and remove emerging pollutants and their degradation by-products in environmental matrices.
... Then, template removal is carried out to achieve the final MIPs with complementary cavities to the used template. MIPs can be formed from organic compounds [10,11], inorganic compounds [8,9], or their combination to devise hybrid materials [12][13][14]. Understanding the interaction between template and the chosen functional monomers plays crucial role in fabrication of MIPs. According to the nature of this interaction, two main approaches are reported including: self-assembling (non-covalent) and preorganized (covalent) approaches, summarized in Table 1. ...
Molecularly imprinted polymers (MIPs) are well historically known class of material that have wide range of applications. Regarding chemical analysis, MIPs could replace biogenic materials, such as antibodies, to impart the required selectivity for analytical method. Apart from other purposes, preparing a MIP for analysis requires particular attention to certain aspects critically affecting the overall efficiency of the imprinting process. In this review we emphasized the critical steps during MIP preparation and characterization that would significantly affect the assessment of imprinting efficiency. MIP preparation starts with the selection of suitable monomers based on the nature of the used template. The template tends to form a stable complex with the used monomers. According to the type of bond formed between template and monomer molecules, three imprinting approaches are reported: covalent, non-covalent, and semi covalent. Then, polymerization of that complex takes place to produce MIP with template occupied binding sites or imprint cavities. So, for the completion of imprinting process and hence vacant cavity production, a suitable effective extraction technique is used. The assessment of template extraction process can be either direct, by template detection in the washing solution, or indirect, by measuring certain physical property of the polymer before and after template removal. Finally, the different parameters determined to assess the imprinting efficiency were summarized and the different sources of errors were addressed.
... The detection performance of this probe was superior to or at least comparable to several reported TC detection methods in terms of linear range and detection limit. Moreover, other methods usually required preprocessing, which were time consuming and expensive [11,13,14], and this method can achieve rapid visual detection. ...
... The detection performance of this probe was superior to or at least comparable to several reported TC detection methods in terms of linear range and detection limit. Moreover, other methods usually required preprocessing, which were time consuming and expensive [11,13,14], and this method can achieve rapid visual detection. More interestingly, as shown in Figure 5, the probe can not only realize the rapid visual detection of TC, but can also distinguish OTC from TC through different fluorescent emission channels. ...
Tetracycline (TC) and oxytetracycline (OTC) are the most widely used broad-spectrum antimicrobial agents in tetracycline drugs, and their structures and properties are very similar, so it is a great challenge to distinguish and detect these two antibiotics with a single probe at the same time. Herein, a dual-channel fluorescence probe (SiCDs@mMIPs-cit-Eu) was developed by integrating two independent reaction sites with SiCDs-doped mesoporous silica molecular imprinting group and europium complex group into a nanomaterial. The synergistic influence of inner filter effect and “antenna effect” can be guaranteed to solve the distinction between TC and OTC. Moreover, this novel strategy can also sequentially detect TC and OTC in buffer solution and real samples with high sensitivity and selectivity. This method revealed good responses to TC and OTC ranging from 0 to 5.5 μM with a detection limit of 5 and 16 nM, respectively. Combined with the smartphone color-scanning application, the portable and cheap paper-based sensor was designed to realize the multi-color visual on-site detection of TC and OTC. In addition, the logic gate device was constructed according to the fluorescence color change of the probe for TC and OTC, which provided the application possibility for the intelligent detection of the probe.
... In the past few years, many molecularly imprinted polymers (MIPs) for tetracycline have been designed using the principle of adsorption. [12][13][14][15] However, a few MIPs have been used as recognition probes to prepare sensors for the determination of the tetracycline. ...
A novel Tetracycline (TC) imprinted polymer was prepared in visible light via synergy of dual functional group monomers methacrylic acid (MAA) and itaconic acid (IA) for selective detection of TC in Urine and milk samples. Surface Plasmon resonance (SPR) and reversible addition chain transfer mechanism (RAFT) were employed in combination with 4-cyano-4-[(dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid (CDTPA) in the presence of ethylene glycol dimethacrylate (EGDMA) as cross linker. In addition, the ratio of template, IA, MAA and EGDMA was optimized (0.8: 0.3: 5: 9) by real time monitoring in SPR. The surface of TC imprinted sensor chip was characterized by contact angle measurement, Fourier Transfer Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). (IA-MAA@SPR)MIPs sensor chip displayed high adsorption capacity and selectivity in comparison to other analogues and non-imprinted polymers (NIPs) based sensor chips. Through 7 adsorption−desorption cycles, the (IA-MAA@SPR)MIPs sensor chip exhibited a good recoverability. These features suggested that the IA-MAA based sensor chip was ideal candidate for the detection of TC. Consequently, within the concentration range of 1×10-13 - 1×10-7 mol/L, the reflectivity changes verses negative logarithm of concentrations presented excellent linearity; R2 = 0.99. Based on linear equation, IA-MAA@SPR MIPs sensor chip showed lower values for limit of detection (LOD) and Limit of quantification (LOQ) i.e. 1.38 × 10-14 mol/L and 4.5 × 10-14 mol/L, respectively. Furthermore, influence of matrix on sensor chip was successfully analyzed in real samples with satisfactory outcomes. Hence, IA-MAA based MIPs in combination with SPR sensor chip demonstrated potential application perspectives for rapid and effective sensing even in the complicated matrices.
... The demand for a robust and efficient sample preparation technique for the selective isolation and preconcentration of polar and ionizable com pounds like tetracyclines at their trace and ultra-trace level concentration from complicated sample matrix, such as milk, cannot be overemphasized. Owing to the complexity of milk as a sample matrix containing lipids, proteins, vitamins, minerals, fats and many other matrix interferants, different sample preparation techniques such as liquid-liquid extraction [15], solid phase extraction [16,17], molecularly imprinted polymers [18,19], dispersive solid phase microextraction [6], solid phase microextraction [20], magnetic solid phase extraction [21], microextraction by packed sorbent [22] and mixed mode solid phase extraction containing anion exchanger [23] are noteworthy. Due to the existence of tetracyclines in ionic states (positively charged, negatively charged or zwitterionic state based on the pH of the sample matrix), most of the sample preparation techniques require matrix pH adjustment to maximize the extraction recovery. ...
Herein, a new extraction mode of classical fabric phase sorptive extraction (FPSE), namely mixed-mode strong cation exchanging FPSE is presented and evaluated for the first time for the determination of tetracycline residues in milk, after protein precipitation. FPSE is a microextraction technique characterized by high chemically stable sorbent, higher analyte retention capacity and faster analyte diffusion capability, where the target analytes interact with the extraction sorbent during the pre-treatment process via a plethora of intermolecular/interionic interactions exerted by different functional moieties implanted on the sponge-like porous sol-gel sorbent network. Subsequently, the selectively retained analytes are eluted using a small volume of solvent system. A novel extraction membrane containing sol-gel C18/propyl sulfonic acid, a mixed mode sorbent consisting of neutral, C18 and strong cation exchanger, propyl sulfonic acid (C3H6SO3⁻) coated on 100% cotton cellulose fabric substrate was designed, synthesized, characterized and evaluated for the selective isolation of four tetracycline antibiotic residues from milk samples.
For quantitative analysis, high performance liquid chromatography coupled with a UV detector (at 350 nm) was used. The method was validated according to the 2002/657/EC decision with regards to linearity, selectivity, stability, limits of detection and quantitation (LOD/LOQ), decision limit, detection capability, trueness, precision and ruggedness, according to the Youden’s test. Recoveries ranged between 88.9 and 122.4%, while the LOD and LOQ were obtained at 15 μg kg⁻¹ and 50 μg kg⁻¹, respectively. Finally, the composite analytical method was applied to monitor the presence of residual tetracyclines in milk samples purchased from a local Greek market.
... It is worth noting that ordered mesoporous silica (OMSiO 2 )-based molecular sieves have been found to perform better than conventional molecular sieves for the extraction and preconcentration of food contaminants, which significantly improves the following detection parameters: accuracy, precision, selectivity and sensitivity (Yang, Hu, & Dong, 2015;Zhang, Li, Wang et al., 2019). OMSiO 2 (support material) and MIPs can also be used to synthesize new molecularly-imprinted organic-inorganic hybrid molecular sieves (OMSiO 2 @MIPs), which combine the high selectivity of MIPs with the binding capacity of OMSiO 2 (Lv, Wang, Yang, Zhao, & Sun, 2012;Yang et al., 2015;Wang, Yan, Yang, Li, & Qiao, 2016;Casado et al., 2017). These types of composite materials are commonly known as MOFs. ...
Background
Molecular sieves are materials with selective sorption properties, and are used to separate or load mixtures of compounds based on their molecular shape and size. These materials are usually made from porous materials and molecularly imprinted polymers (MIPs).
Scope and approach
Although molecular matrices can be manufactured from either inorganic porous materials or MIPs, the former have been used more widely in the different fields of science and technology. Specifically, MIPs have been little studied as molecular sieves for food applications, as they have only very recently been introduced materials in this field. For this reason, in this review we focus on molecular sieves prepared from porous materials.
Key findings and conclusions
Molecular matrices have been mainly used as materials for food packaging, food nanoreactors, the absorption of pathogens, the controlled and sustained release of active compounds and enzymes, the stabilization and immobilization of active substances and enzymes, the detection and removal of food contaminants, and in the development of intelligent food contact materials. All these aspects are extensively reviewed in this manuscript, with particular emphasis on the literature published during the last five years.
... Molecularly imprinted polymer (MIP) is a type of synthetic material that has specific recognition ability, so this kind of material has been used to develop many extraction methods for the different analytes (Kubo and Otsuka 2016). By now, there have been some papers reporting the use of MIP as absorbent to develop the extraction methods for TCs (Feng et al. 2016;Jing et al. 2009Jing et al. , 2010Lv et al. 2012;Lian et al. 2012;Sánchez-Polo et al. 2015), but there have been only two MIP-based dispersive solid phase extraction methods reported to extract TCs (Chen et al. 2009;Kong et al. 2012). As discussed above, a sample preparation method simultaneous containing the merits of DSPME, MOF, and MIP is desirable. ...
... As shown in Table 1, MIP-MOF simultaneously recognized the 7 drugs, and the absorption capacities were in the range of 2200-3000 ng/mg. The previously reported MIP materials for TCs recognized at most 4 drugs (Feng et al. 2016;Jing et al. 2009Jing et al. , 2010Lv et al. 2012;Lian et al. 2012;Sánchez-Polo et al. 2015;Chen et al. 2009;Kong et al. 2012;Wang et al. 2018), so the recognition spectrum of the present MIP material was broader than those MIPs. Furthermore, the matrix-matched solutions of the 7 TCs (100 ng/mL) were used to evaluate the MIP-MOF-DSPME method. ...
In this study, the molecularly imprinted nano-polymer of minocycline was polymerized on the surface of a metal organic framework material to synthesize a novel composite. This composite was used as absorbent to develop a dispersive solid phase microextraction method for extraction of 7 tetracyclines in chicken muscle followed by determination with ultra performance liquid chromatography. The composite achieved high absorption capacities (2200–3000 ng/mg) and high recoveries (> 92%) for the 7 tetracyclines, and could be reused for 8 times. Due to the high enrichment factors (18–37), the limits of detection for the 7 drugs were in the range of 0.2–0.6 ng/g, and the limits of quantification were in the range of 0.5–2.0 ng/g. The recoveries of the 7 drugs from standard-fortified blank chicken muscle sample were in the range of 69.6–94.7%. Therefore, this method could be used as a practical tool for multi-detection of the residues of tetracyclines in meat.
... However, the nonprudent use of OTC in animals leads to accumulation of the residues in animal products such as milk. Small doses of antibiotic exposure to humans through the food chain poses health threats including hypersensitivity [1,2], antibacterial drug resistance [3], and toxic effects [4]. In protecting the public from exposure to residues, different regulatory organizations (Food and Agriculture Organization, European Union, and Food and Drug Authority) have set a maximum residue limit (MRL) of 0.1 mg/L in milk [4][5][6]. ...
A novel tantalum pentoxide nanoparticle-electrochemically reduced graphene oxide nanocomposite-modified glassy carbon electrode (Ta 2 O 5-ErGO/GCE) was developed for the detection of oxytetracycline in milk. The composition, structure and morphology of GO, Ta 2 O 5 , and Ta 2 O 5-ErGO were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Oxytetracycline electrochemical behavior on the bare GCE, GO/GCE, ErGO/GCE, and Ta 2 O 5-ErGO/GCE was studied by cyclic voltammetry. The voltammetric conditions (including scan rate, pH, deposition potential, and deposition time) were systematically optimized. With the spacious electrochemical active area, the Ta 2 O 5-ErGO/GCE showed a great magnification of the oxidation signal of oxytetracycline, while that of the other electrodes (GCE, GO/GCE, ErGO/GCE) could not reach the same level. Under the optimum conditions, the currents were proportional to the oxytetracycline concentration in the range from 0.2 to 10 µM, and a low detection limit of 0.095 µM (S/N = 3) was detectable. Moreover, the proposed Ta 2 O 5-ErGO/GCE performed practically with satisfactory results. The preparation of Ta 2 O 5-ErGO/GCE in the current work provides a minor outlook of detecting trace oxytetracycline in milk.
... However, the widespread use of TC antibiotics results in trace levels of antibiotic residues in animal-derived food, which poses adverse effects on health [1]. The European Union, US Food and Drug Administration, and Chinese Ministry of Agriculture have established maximum residue limit (MRL) in different foods, such as the MRL of TC in milk is 0.1 mg·kg −1 [2]. Therefore, the determination of TC residues is very important to ensure food safety. ...
A method is reported for in-situ detection of the antibiotic tetracycline (TC). It is based on a combination of extraction of TC by magnetic molecularly imprinted polymers nanoparticles (MMIPs NPs) and detection by surface plasmon resonance (SPR). The TC-captured MMIPs NPs were flowed over the surface of the SPR chip that was modified with mercaptoethylamine. The SPR signal undergoes a strong increase through the use of MMIPs NPs. It increases linearly in the 5.0–100 pg·mL⁻¹ TC concentration range, and the detection limit is as low as 1.0 pg·mL⁻¹ (at S/N = 3). This method shows selectivity to TC compared with structurally analogues. In order to demonstrate the power of the method, it was applied to the analysis of milk spiked with TC. These results were validated by comparing them to those of an enzyme-linked immunoassay. The average recovery is in the range of 95.7–104.6%.
Graphical abstractSchematic representation of a surface plasmon resonance assay for the sensitive determination of tetracycline in milk using the magnetic molecularly imprinted polymers nanoparticles that can extract tetracycline and amplify the SPR signal.
