Template Molecule Research Articles

Towards Molecularly Imprinted Polypyrrole-Based Sensor for the Detection of Methylene Blue

This study is dedicated to molecularly imprinted polymer-based sensor development for methylene blue detection. The sensor was designed by molecular imprinting of polypyrrole with phenothiazine derivative methylene blue (MB) as a template molecule. The molecularly imprinted polymer (MIP) was deposited directly on the surface of the indium tin oxide-coated glass electrode by potential cycling. Different deposition conditions, the layer’s durability, and thickness impact were analysed. The working electrodes were coated with molecularly imprinted and non-imprinted polymer layers. Potential pulse chronoamperometry and cyclic voltammetry were used to study these layers. Scanning electron microscopy was used to determine the surface morphology of the polymer layers. The change in optical absorption was used as an analytical tool to evaluate the capability of the MIP layer to adsorb MB. Selectivity was monitored by tracking the optical absorption changes in the presence of Azure A. In the case of MB adsorption, linearity was observed at all evaluated calibration plots in the concentration range from 0.1 μM to 10 mM. The novelty of this article is based on the methodology in the fabrication process of the sensors for MB, where MB retains its native (non-polymerised) form during the deposition of the MIP composite.

Fabrication of a novel molecularly imprinted biosensor assisted by higher-order calibration methods and a computer-generated experimental design for determination of thyroglobulin in the presence of thyroxine and triiodothyronine as uncalibrated interference

In this work, a novel electrochemical biosensor was fabricated by modification of a rotating glassy carbon electrode (GCE) with fullerene C60-ionic liquid (C60-IL), and electrochemical synthesis of molecularly imprinted polymers (MIPs) on its surface for selective and sensitive determination of thyroglobulin (TG) in the presence of thyroxine (T4) and triiodothyronine (T3) as uncalibrated interference. The MIPs were synthesized onto the surface of electrochemically activated C60-IL/GCE by electropolymerization of 4-aminothiophenol, methacrylic acid, ethylene glycol dimethacrylate (as cross linker), and TG (as template molecule). By incubation of the biosensor in TG solution, the TGs were entrapped within the pathways of the MIPs, and by incubation of the biosensor in electrochemical probe solution, the pathways for reaching the probe molecules to biosensor were decreased which caused the hydrodynamic differential pulse voltammetric (HDPV) response of the biosensor to be decreased. The effects of experimental parameters on response of the biosensor were optimized by a quadratic central composite design, and at optimized conditions determination of TG in the presence of T4 and T3 as uncalibrated interference was performed. The selectivity of the biosensor was further assisted by supporting the biosensor response with the help of second-order calibration methods and generation of second-order HDPV data with the aim of exploiting second-order advantage. Second-order calibration models were developed by MCR-ALS, PARAFAC2, N-PLS/RBL, and U-PLS/RBL with the aim of choosing the best model for assisting the biosensor for selective determination of the TG in the presence of T4 and T3 as uncalibrated interference. The results confirmed the best performance was observed for the biosensor assisted by PARAFAC2 in both synthetic and real matrices which was comparable with HPLC-UV as the reference method, and can be suggested as an alternative method for chromatographic methods.

Derivation of Highly Predictive 3D-QSAR Models for hERG Channel Blockers Based on the Quantum Artificial Neural Network Algorithm.

The hERG potassium channel serves as an annexed target for drug discovery because the associated off-target inhibitory activity may cause serious cardiotoxicity. Quantitative structure-activity relationship (QSAR) models were developed to predict inhibitory activities against the hERG potassium channel, utilizing the three-dimensional (3D) distribution of quantum mechanical electrostatic potential (ESP) as the molecular descriptor. To prepare the optimal atomic coordinates of dataset molecules, pairwise 3D structural alignments were carried out in order for the quantum mechanical cross correlation between the template and other molecules to be maximized. This alignment method stands out from the common atom-by-atom matching technique, as it can handle structurally diverse molecules as effectively as chemical derivatives that share an identical scaffold. The alignment problem prevalent in 3D-QSAR methods was ameliorated substantially by dividing the dataset molecules into seven subsets, each of which contained molecules with similar molecular weights. Using an artificial neural network algorithm to find the functional relationship between the quantum mechanical ESP descriptors and the experimental hERG inhibitory activities, highly predictive 3D-QSAR models were derived for all seven molecular subsets to the extent that the squared correlation coefficients exceeded 0.79. Given their simplicity in model development and strong predictability, the 3D-QSAR models developed in this study are expected to function as an effective virtual screening tool for assessing the potential cardiotoxicity of drug candidate molecules.

Dual‐emission ratiometric fluorescence sensors based on silica, molecularly imprinted polymers and carbon quantum dots for high‐sensitivity and high‐selectivity detection of sulfadiazine

AbstractIn this work, a dual‐emission ratiometric fluorescence sensor was prepared and used for the detection of sulfadiazine (SDZ) drug. The hydrothermal method was used to synthesize carbon quantum dots (CQD) (fluorescence response signal) and sulfhydryl‐modified cadmium telluride quantum dots (fluorescence reference signal), and a molecularly imprinted polymer was subsequently synthesized. After eluting the template molecule SDZ, the blot recognition site remains on the surface of the imprinted polymer. During the process of detection, due to electron transfer between SDZ and CQDs, holes of stimulated electrons are filled. This leads to fluorescence quenching at around 430 nm, which greatly improves sensor selection performance. Compared with traditional single‐emission fluorescence sensors, ratiometric fluorescence sensors have a wider linear range and higher detection accuracy. Under the optimal conditions, the sensor exhibited excellent performance in terms of low detection limit (4.2 nmol L−1) and satisfactory linear range (2–20 μmol L−1). This intelligent response change mode also provides prospect for detection of other sulfonamide antibiotics and offers a reference to signal transform for other molecular imprinting technologies. © 2023 Society of Industrial Chemistry.

Layer-by-layer assembled magnetic molecularly imprinted nanoparticles for highly specific separation of adenosine 5′-monophosphate: Relations between adsorption properties and imprinted layers

Molecularly imprinted polymers (MIPs) are an effective method to accurately recognize and isolate targets. Adenosine 5′-monophosphate (AMPs) are typical nucleoside compounds widely used as intermediates and raw materials in the pharmaceutical field with high medicinal potential. In this work, molecularly imprinted adsorbents with fast magnetic response recovery were obtained for the selective separation of AMP by covering MIPs with AcrU and AM as functional monomers and AMP as a template molecule on the surfaces of Fe3O4 NPs, and then by layer-by-layer (LBL) assembling of the MIPs realized through glutaraldehyde (GA) mediation. Static adsorption experiments have been utilized to explore the adsorption effects of different numbers of imprinted layers. The experimental results showed that the Fe3O4@MIPs-LBL2 covered with two layers of MIPs had the best imprinting effect (IF = 2.50), and the adsorption of AMP by Fe3O4@MIPs-LBL2 was dominated by chemisorption, with the saturation adsorption capacity reaching 105.72 μmol g−1, it could adsorb and separate AMP efficiently from the actual sample (human urine). The magnetic responsiveness solves the problem of difficult recovery and high recovery loss of nano-imprinted adsorbents. Notably, this work not only proposes a magnetic imprinted adsorbent for selective separation of AMP, but also explores the structure-effect relationship between the number of layers of MIPs and adsorption performance, which provides a new inspiration for improving the performance of molecular imprinting techniques.

Electrochemical sensing of monoterpene phenols in plant essential oils using a molecularly imprinted polymer dual-template sensor

Monoterpene phenols are naturally occurring aromatic compounds found in plant essential oils, contributing to their distinct flavors, fragrances, and medicinal properties. Thymol and carvacrol, major constituents of thyme and oregano essential oils, have garnered significant attention due to their diverse biological activities. Here, we propose the development of a novel double template molecular imprinted electrochemical sensor (DT-MIP sensor) for the selective and simultaneous detection of thymol and carvacrol. The sensor's performance was optimized by varying the quantity of functional monomer, cross-linker, and template molecules during MIP synthesis. The DT-MIP sensor demonstrated superior recognition properties and high sensitivity, with detection limits of 0.11 μM for carvacrol and 0.24 μM for thymol. Selectivity tests confirmed minimal interference from potential interfering agents. GC-MS analysis validated the sensor's accuracy in detecting thymol and carvacrol concentrations in thyme and oregano essential oils. The simplicity, cost-effectiveness, and portability of the DT-MIP sensor offer promising applications in food quality control, environmental monitoring, and medical diagnostics.

Electrochemical chiral sensor for levofloxacin detection base on Cu/Fe-BTC amplification.

The key to developing sensors for chiral drug determination is to exclude interference from enantiomers. In this study, metal-organic frameworks (MOFs) and molecularly imprinted polymer (MIP) were introduced to prepare a chiral sensor for levofloxacin detection. The MIP was electropolymerised on the surface of the Cu/Fe-benzene-1,3,5-tricarboxylate MOF (Cu/Fe-BTC)-modified Au electrode using levofloxacin as a template molecule. After eluting the levofloxacin, a chiral sensor with recognition sites for levofloxacin was obtained. With this site as a switch, a novel method for detecting levofloxacin was established. Because of the enhanced recognition effect, the sensor can effectively exclude the enantiomeric interference of d-ofloxacin. Moreover, Cu/Fe-BTC can effectively amplify the current response signal and improve the sensitivity of thesensor. The linear range of the sensor was 5 to 4000 × 10-11mol L-1, and the detection limit was 2.07 × 10-11mol L-1. Whenapplied to detecting levofloxacin in actual samples, the sensor showed a 92.7-109.8% recovery.

A novel molecularly imprinted electrochemical sensor for the ultrasensitive detection of tert-butylhydroquinone in edible oils

Tert-butylhydroquinone (TBHQ) is widely used to increase the stability of food products; however, it is considered to be a highly unsafe preservative ingredient that has caused serious damage to human health. Thus, in this paper, a novel molecularly imprinted electrochemical sensor was designed for ultrasensitive, and selective detection of TBHQ in edible oils. The sensor was based on the molecularly imprinted polymer (MIP) synthesized with multiwalled carbon nanotube (MWCNT), and gold nanoparticle (GNP), as the coating materials, o-phenylenediamine (o-PDA) as the functional monomer, and TBHQ as the template molecule. The electrochemical behavior of MIP/GNP/MWCNT/GCE was studied using several electrochemical methods, which showed a low detection limit of 5 nM. Furthermore the sensor demostrated excellent stability, selectivity, repeatability, and reproducibility. It was successfully used to detect TBHQ in edible oils, with recoveries ranging from 98.44% to 102.09% and relative standard deviations (RSDs) of less than 2.16%, indicating that TBHQ detection in actual samples is both possible and accurate.

A dual action electrochemical molecularly imprinted aptasensor for ultra-trace detection of carbendazim

Carbendazim is often used in agriculture to prevent crop diseases, even though it has been associated with health concerns. To ensure the safety of food products and comply with environmental regulations, an ultrasensitive method for carbendazim determination must be developed. In this study, a new electrochemical molecularly imprinted polymer-aptasensor based on hemin-Al-metal organic framework@gold nanoparticles (H-Al-MOF@AuNPs) was developed for sensitive and selective carbendazim detection. Hemin linked to the surface of the Al-metal organic framework also possesses outstanding peroxidase-like qualities that can electrocatalyse the reduction of H2O2. Thus, H-Al-MOF functions as an in-situ probe. Additionally, AuNPs offer many binding sites to load carbendazim aptamers and create an imprinted polymer-aptasensing interface. Dopamine is the chemical functional monomer in the electropolymerised film, while carbendazim is the template molecule. Thus, compared to the molecularly imprinted polymer or aptasensor alone, the molecularly imprinted polymer-aptasensor showed greater selectivity due to the synergistic action of the polymer and carbendazim aptamer towards carbendazim. A decrease in peak current was observed by differential pulse voltammetry (DPV) and chronoamperometry (CA) as the concentration of carbendazim increased. This possibly resulted from carbendazim connecting to the carbendazim aptamer and simultaneously blocking the imprinted polymer cavities on the surface of the modified electrode, which reduced the transfer of electrons. Signals were observed for hemin DPV and H2O2 catalytic reduction CA. DPV and CA showed that the linear ranges for carbendazim were 0.3 fmol L-1-10 pmol L-1 and 0.7 fmol L-1-10 pmol L-1, respectively, with limits of detection of 80 and 300 amol L-1. Satisfactory recoveries were obtained with tap water, apple juice, and tomato juice samples, demonstrating that the proposed sensor has potential for food and environmental analysis.

PEDOT wrapped biomimetic recognition system for selective determination of carcinogenic phenacetin content in drug samples

A molecular imprinted polymeric (MIP) recognition system comprising of PEDOT swaddled CoWO4 nanocapsules has been developed for the electrochemical detection of carcinogenic phenacetin drug. Facile hydrothermal route was employed to synthesize CoWO4 whereas, EDOT was wrapped around under chemical polymerization at room temperature. A series of characterizations revealed that electrostatic interactions generated between thiophene sulfur of PEDOT and metal atoms of CoWO4 have prompted the homogeneously wrapped molecularly imprinted nanocomposite. The obtained peak potential plotted against the CV scan rate revealed involvement of 2 electrons in the electroxidation detection process of phenacetin. The values of charge transfer coefficient α (0.69) and charge transfer rate constant ks (2.24 s−1) at electrode-electrolyte interface during the detection procedure were also evaluated. The nanoarchitecture of the designed MIP exhibited abundant imprinted sites to selectively bind the template molecule in terms of shape, size and functionalities resulted in significant augmentation in sensitivity (0.14 µA nM−1 cm−2) and a very low detection limit (0.091 nM). Phenacetin content in homeopathic and allopathic drug samples were successfully quantified with more than 95 % accuracy by employing the MIP modified electrode. The present research introduces new possibilities for identification of carcinogenic phenacetin used as adulterants in various narcotic drug samples.

Investigative on the molecular mechanism of novel antioxidation peptides by 3D-QSAR, in vitro assay and MD simulations

Three novel antioxidant peptides MHW, YHW and FHW were designed by the analysis of 3D-QSAR. Two accurate CoMFA (Q2 = 0.886 and R2 = 0.988) and CoMSIA (Q2 = 0.737 and R2 = 0.955) models were established. The FTC assay showed that activities of the new peptides on lipid peroxidation is significantly better than that of the template molecule LHW. The results of erythrocyte hemolysis assay demonstrated that MHW, YHW and FHW significantly inhibited AAPH-induced erythrocyte hemolysis by scavenging free radicals at the cellular level. It caused the restoration of intracellular antioxidant enzyme (GSH, CAT and SOD) activities at an acceptable pace and the silencing of intracellular MDA formation. Furthermore, MTT toxicity assay showed that the novel antioxidant peptides had good biocompatibility and no cytotoxicity. Molecular docking and molecular dynamics simulations were used to investigate the molecular mechanism. The results showed that Ser363, Arg380, Asn414 and Arg415 residues played key roles in the antioxidant activity of MHW, YHW and FHW. And they mainly binded to the important residues of Keap1 protein stably by electrostatic force, van der Waals force, H-bonds and hydrophobic interactions, which can better fit the Kelch pocket structural domain of Keap1. Therefore, MHW, YHW and FHW had strong potential to interfere with Keap1-Nrf2 interaction and promoted the enzymatic expression of Nrf2-ARE downstream target pathway.

N-doped carbon dots coupled with molecularly imprinted polymers as a fluorescent sensor for ultrasensitive detection of genistein in soya products.

Rapid detection of genistein in soya products has remained difficult. Current methods necessitate sample handling and use of costly instruments. Here, using a simple one-pot reverse microemulsion method, a sensor based on N-doped carbon dots conjugated molecularly imprinted polymers (N-CDs@MIPs) was synthesized to analyze genistein. N-doped carbon dots were used as fluorescent component, genistein as the template molecule, and molecularly imprinted polymers as the selective sorbent in this fluorescence sensor. The sensor was then examined and optical studies demonstrated that N-CDs@MIPs not only had strong fluorescence emission and outstanding optical stability, but also had good sensitivity (detection limit 35.7nM) and selectivity to genistein. Furthermore, the N-CDs@MIPs materials were used to analyze genistein in soya products, and the findings (which ranged from 99.77% to 106.11%) show that the N-CDs@MIPs has high potential for quickly detecting the amount of genistein in complicated food samples.

Leveraging the relative strengths of hydrogen and halogen bonds to control nanostructures

Halogen bonds (XBs) and hydrogen bonds (HBs) present a straightforward yet effective strategy for controlling nanostructure morphology. The self-assembled nanopattern, modulated by the relative strengths of XBs and HBs, has rarely been studied using analogous molecules. This research systematically evaluates the relationship between the strengths of Br···O hetero-XBs and N···H HBs in directing the formation of 2D supramolecular co-assembled structures. In this work, tetracarboxylic acid (PEDA), featuring four carboxyl substitutions, forms a stable hydrogen-bonded Rosette network that can function as a template for trapping guest molecules of complementary shape and size. The star-shaped bromine-substituted 1,3,5-tris(3,5-dibromophenyl)benzene (TDB) and 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) serve as XB donor and HB acceptor respectively, thus capable of acting as guest molecules co-assembly with the PEDA at the heptanoic acid/HOPG interface. Bimolecular co-assembly patterns resulting from these combinations were investigated using scanning tunneling microscopy (STM) and supported by density functional theory (DFT) calculations. The findings indicate that TDB molecules can be accommodated within the triangular cavities of the Rosette network due to the weaker Br···O hetero-XB. Concurrently, the similar star-shaped TPT can co-assemble with PEDA to form an acid–pyridine–acid Ladder-like network based on stronger N···H HBs. Therefore, Br···O hetero-XBs seemingly play no decisive role in the coassembly process of PEDA and TDB. Conversely, N···H HBs hold evident significance in the coassembly of PEDA and TPT. This work potentially holds substantial value for the future design and customization of devices employing the interplay of XBs and HBs.

Fabrication of an electrochemical sensor based on molecular imprinting technology for detecting elemene

This paper presents the fabrication of an electrochemical sensor based on molecular imprinting technology for the detection of elemene, a bioactive compound with various pharmacological activities. The sensor was prepared by electrochemically polymerizing acrylamide and N,N-methylenebisacrylamide in the presence of dopamine hydrochloride and phytic acid as functional monomers, with elemene as the template molecule. The resulting molecularly imprinted polymer film on the glassy carbon electrode exhibited specific recognition sites for elemene. The sensor's electrochemical performance was systematically investigated using cyclic voltammetry and electrochemical impedance spectroscopy. The sensor showed excellent selectivity, sensitivity, stability, and reproducibility for elemene detection. The optimized sensor parameters, such as the number of polymerization cycles and elution time, were determined. The sensor exhibited a linear response to elemene in the concentration ranges of 10 μM to 0.1 mM and 50 nM to 10 μM, with a detection limit of 2.7 nM. The proposed electrochemical sensor offers a rapid, label-free, and selective detection platform for elemene, eliminating the need for complex sample preparation and expensive labeling reagents. It has the potential for application in quality control, safety assessment, and therapeutic efficacy evaluation of elemene-containing products.

Recent Developments in the Detection of Organic Contaminants Using Molecularly Imprinted Polymers Combined with Various Analytical Techniques.

Molecularly imprinted polymers (MIPs) encompass a diverse array of polymeric matrices that exhibit the unique capacity to selectively identify a designated template molecule through specific chemical moieties. Thanks to their pivotal attributes, including exceptional selectivity, extended shelf stability, and other distinct characteristics, this class of compounds has garnered interest in the development of highly responsive sensor systems. As a result, the incorporation of MIPs in crafting distinctive sensors and analytical procedures tailored for specific analytes across various domains has increasingly become a common practice within contemporary analytical chemistry. Furthermore, the range of polymers amenable to MIP formulation significantly influences the potential utilization of both conventional and innovative analytical methodologies. This versatility expands the array of possibilities in which MIP-based sensing can be employed in recognition systems. The following review summarizes the notable progress achieved within the preceding seven-year period in employing MIP-based sensing techniques for analyte determination.

A novel and intelligent molecularly imprinted enzymatic biosensor for biosensing of human serum albumin in the presence of gamma-globulin, and glucose as uncalibrated interference

Human serum albumin (HSA) is not electroactive, because the electroactive amino acids have been buried in its structure. Therefore, direct electrochemical determination of the HSA as the most abundant protein in human plasma cannot be performed. In this work, a novel electrochemical biosensor has been developed based on synthesis of dual templates molecularly imprinted polymers (DTMIPs) having trypsin (TRP) and HSA as template molecules onto the surface of a glassy carbon electrode (GCE) modified with graphene-ionic liquid (Gr-IL). By incubation of the biosensor with TRP, and HSA, tryptic hydrolysis of the HSA is occurred which breaks the HSA down into free amino acids. The HSA involves five electroactive amino acids including cysteine, tryptophan, tyrosine, methionine and histidine whose differential normal pulse voltammetric (DNPV) responses are overlapped and generated a single peak. In order to increase the sensitivity of the DTMIP/Gr-IL/GCE for determination of the HSA, hydrodynamic DNPV (HDNPV) data were generated, and used for analytical purposes. The second-order HDNPV data were generated at different pulse amplitudes and used to develop four second-order calibration models by multivariate curve resolution-alternating least squares (MCR-ALS), parallel factor analysis2 (PARAFAC2), multi-way partial least squares/residual bilinearization (N-PLS/RBL), and unfolded partial least squares/residual bilinearization (U-PLS/RBL) to select the best procedure for determination of the HSA in the presence of gamma-globulin and glucose as uncalibrated interferences. The results confirmed the best performance for the biosensor assisted by MCR-ALS for ultrasensitive and selective determination of the HSA in both synthetic and real matrices which was comparable with HPLC-UV as a reference method.

Molecular action mechanisms of two novel and selective calcium release-activated calcium channel antagonists

The prototypical calcium release-activated calcium (CRAC) channel, composed of STIM1 and Orai1, is a sought-after drug target for treating autoimmune disorders. Herein, we identified two novel and selective CRAC channel inhibitors, the indole-like compound C63368 and pyrazole core-containing compound C79413, potently and reversibly inhibiting the CRAC channel with low micromolar IC50s and sparing various off-target ion channels. These two compounds did not inhibit STIM1 activation or its coupling with Orai1, nor did they affect the channel's calcium-dependent fast inactivation. Instead, they directly acted on the Orai1 protein, with the channel's pore geometry profoundly affecting their potencies. In vitro, C63368 and C79413 effectively inhibited Jurkat cell proliferation and cytokines production in human T lymphocytes. Intragastric administration of C63368 and C79413 to mice yielded great therapeutic benefits in psoriasis and colitis animal models of autoimmune disorders, reducing serum cytokines production and significantly relieving pathological symptoms. It's worth noting, that this study provided the first insight into the characterization and mechanistic investigation of an indole-like CRAC channel antagonist. Altogether, the identification of these two highly selective CRAC channel antagonists, coupled with the elucidation of their action mechanisms, not only provides valuable template molecules but also offers profound insights for drug development targeting the CRAC channel.

Synthesis of molecularly imprinted polymer for the removal of cyanazine from aqueous samples

BackgroundCyanazine (CYZ) is one of the triazine herbicides to prevent broadleaf grass and weeds in crops. Despite its affordability and productivity in increasing crop yield, the extensive usage of CYZ contributes to environmental pollution and poses risks to living organisms. Most research has focused on detecting CYZ in the environment and its toxicity to humans and the ecosystem. For these reasons, molecular imprinting technology (MIT) can be applied to produce an effective adsorbent material of high binding affinity and selectivity towards its target compound which is known as molecularly imprinted polymers (MIPs). In this study, MIP was prepared by precipitation polymerization using CYZ as a template molecule, methacrylic acid (MAA), acrylamide (AAm) and 4-vinylpyridine (4VP) as functional monomers, and ethylene glycol dimethacrylate (EGDMA) as cross-linker in the ratio of 1:6:12, respectively. The effects of contact time, initial concentration, pH, and polymer dosages on the adsorption efficiencies of MIPs were also investigated in this study.ResultsMIPs of CYZ were successfully synthesized by precipitation polymerization method with a non-covalent approach using different functional monomers such as methacrylic acid (MAA), acrylamide (AAm) and 4-vinylpyridine (4VP). For the comparison study, the non-imprinted polymer (NIP) was synthesized without the addition of CYZ, the template molecule. The FTIR analysis indicated the interactions among CYZ and functional monomers (MAA, AAm or 4VP) in the presence of EGDMA as a cross-linker. The FESEM analysis showed that only MIP (AAm) and NIP (AAm) had regular and spherical polymer particles while MIP (MAA), NIP (MAA), MIP (4VP) and NIP (4VP) were agglomerated and irregular in shape. The EDX analysis showed that the MIPs were mainly composed of carbon and oxygen. Meanwhile, the BET analysis of MIP (AAm) had higher surface area, total pore volume and average pore radius than that NIP (AAm). Based on the batch binding study, MIP (AAm) (83.30%) had the highest binding efficiency than the MIP (MAA) (76.96%) and MIP (2VP) (76.90%) at a contact time of 240 min. The optimum conditions for the highest binding efficiency of MIP (AAm) were obtained at an initial concentration of 6 ppm, pH 7 and polymer dosage of 0.1 g polymer beads. The adsorption efficiency of MIP (AAm) with CYZ at the optimum parameters resulted in 86.39%. The selectivity test showed that MIP (AAm) was more selective towards CYZ than AME, the competitive compound with relative selectivity coefficient of 2.36. The kinetic isotherm of MIP (AAm) was best explained according to the pseudo-second-order kinetic model while the adsorption isotherm of MIP (AAm) was based on the Langmuir adsorption isotherm model. The MIP (AAm) was tested in the distilled water (DIW), tap water and river water spiked with CYZ and a substantial amount of CYZ was removed with a recovery of 86.67%, 84.75% and 84.69%, respectively.ConclusionThe MIPs of CYZ were successfully synthesized by the precipitation polymerization method using different functional monomers. Among those MIPs, MIP (AAm) showed the highest rebinding efficiency and therefore this MIP was selected for further studies. The best combination of CYZ, AAm was the main factor that contributed to the morphological and chemical properties, as well as the efficiency and selective binding performance of MIP (AAm). Since MIP (AAm) showed a substantial removal efficiency of CYZ in the environment specifically water sources, it has the capability to act as an adsorbent material for various purposes such as solid-phase extraction techniques and a stationary phase in various chromatographic techniques.Graphical

One-pot preparation of magnetic molecularly imprinted adsorbent with dual template molecules for simultaneously specific capture of sulfonamides and quinolones in water and milk samples

Specific capture is a beneficial tactic in simultaneous monitoring of sulfonamides (SAs) and quinolones (QLs). For this purpose, a new magnetic molecularly imprinted adsorbent based on double-template molecules (DT-MIP@MNA) was facilely prepared by “one-pot” hydrothermal technique and utilized as the adsorbent of magnetic solid-phase extraction (MSPE). Molecular simulation technique was employed to quickly screen functional monomer. The recognition factors of prepared adsorbent towards templates sulfamethazine and nalidixic acid were 5.89 and 2.90, respectively, and the corresponding adsorption capacities were as high as 8.85 mg/g and 8.97 mg/g, respectively. Under the optimized parameters, the proposed DT-MIP@MNA/MSPE was combined with HPLC to simultaneously and selectively monitor trace SAs and QLs residuals in water and milk samples. The achieved limits of detection were 0.012–0.028 μg/L and 0.015–0.032 μg/kg for water and milk samples, respectively. The current supplied a sensitive, reliable and anti-interference method for simultaneously monitoring trace SAs and QLs in food.

Targeted Removal of Galloylated Flavanols to Adjust Wine Astringency by Using Molecular Imprinting Technology.

Excessive galloylated flavanols not only cause instability in the wine but also lead to unbalanced astringency. Although clarification agents are always used to precipitate unstable tannins in wine, the non-specific adsorption of tannins results in the failure to precisely regulate the tannin composition of the wine. In this work, molecularly imprinted polymers (MIPs) with template molecules of galloylated flavanols were designed to specifically adsorb gallotannins to reduce wine astringency. The results showed that the "pores" on the surface of the MIPs are the structural basis for the specific adsorption of the target substances, and the adsorption process is a chemically driven single-molecule layer adsorption. Moreover, in the mono/oligomeric gallotannin-rich model solution, the adsorption of gallotannins by I-MIPs prepared as single template molecules reached 71.0%, and the adsorption capacity of MIPs for monomeric gallotannins was about 6.0 times higher than polymeric gallotannins. Given the lack of technology for the targeted adsorption of tannins from wine, this work explored the targeted modulation of wine astringency by using molecular imprinting techniques.