Carbonized polymer dots-based molecular imprinting: An adsorbent with enhanced selectivity for highly efficient recognition and removal of ceftiofur sodium from complex samples.

Highly selective removal of residual cephalosporin antibiotics from complex systems is crucial for human health and ecological environment protection. Herein, a newly molecularly imprinted polymer adsorbent (CPDs-NH2@MIP) with enhanced selectivity for ceftiofur sodium (CTFS) was developed by using the special carbonized polymer dots (CPDs-NH2) as functional monomer. The CPDs-NH2 has a nano-spherical structure and functionalized groups (CC, -NH2) via the incomplete carbonization polymerization of citric acid, acrylamide and ethylenediamine, which can accurately interact with CTFS by overcoming steric hindrance, resulting in more precisely imprinted sites and reducing non-imprinted regions in MIP. The presented CPDs-NH2@MIP exhibited excellent adsorption capacity for CTFS (68.62 mg g-1), achieving equilibrium within 10 min, and highly selectivity in mixed solution containing five coexisting substances, with an imprinted factor (5.61). Compared with commercial adsorbents and MIPs prepared with traditional chain functional monomers, the CPDs-NH2@MIP showed significant advantage in selective recognition and separation of target. Analysis of microstructure and mechanism proved that usage of the spherical functional monomer generated precise imprinting sites and dense structure in CPDs-NH2@MIP, which effectively enhanced the selectivity in complex system combined with hydrogen bonding interaction. The idea of designing and using spherical functional monomer will promote the practicality of molecularly imprinted polymer adsorbents.

Synthesis of polymerizable betulin maleic diester derivative for dental restorative resins with antibacterial activity.

OBJECTIVE: Bisphenol A glycidyl methacrylate (Bis-GMA) is of great importance for dental materials as the preferred monomer. However, the presence of bisphenol-A (BPA) core in Bis-GMA structure causes potential concerns since it is associated with endocrine diseases, developmental abnormalities, and cancer lesions. Therefore, it is desirable to develop an alternative replacement for Bis-GMA and explore the intrinsic relationship between monomer structure and resin properties. METHODS: Here, the betulin maleic diester derivative (MABet) was synthesized by a facile esterification reaction using plant-derived betulin and maleic anhydride as raw materials. Its chemical structure was confirmed by 1H and 13C NMR spectra, FT-IR spectra, and HR-MS, respectively. The as-synthesized MABet was then used as polymerizable comonomer to partially or completely substitute Bis-GMA in a 50:50 Bis-GMA: TEGDMA resin (5B5T) to formulate dental restorative resins. These were then determined for the viscosity behavior, light transmittance, real-time degree of conversion, residual monomers, mechanical performance, cytotoxicity, and antibacterial activity against Streptococcus mutans (S. mutans) in detail. RESULTS: Among all experimental resins, increasing the MABet concentration to 50 wt% made the resultant 5MABet5T resin have a maximum in viscosity and appear dark yellowish after polymerization. In contrast, the 1MABet4B5T resin with 10 wt% MABet possessed comparable shear viscosity and polymerization conversion (46.6 ± 1.0% in 60 s), higher flexural and compressive strength (89.7 ± 7.8 MPa; 345.5 ± 14.4 MPa) to those of the 5B5T control (48.5 ± 0.6%; 65.7 ± 6.7 MPa; 223.8 ± 57.1 MPa). This optimal resin also had significantly lower S. mutans colony counts (0.35 ×108 CFU/mL) than 5B5T (7.6 ×108 CFU/mL) without affecting cytocompatibility. SIGNIFICANCE: Introducing plant-derived polymerizable MABet monomer into dental restorative resins is an effective strategy for producing antibacterial dental materials with superior physicochemical property.

Bonding of Composite Cements Containing 10-MDP to Zirconia Ceramics Without Dedicated Ceramic Primer.

PURPOSE: To measure zirconia-to-zirconia microtensile bond strength (µTBS) using composite cements with and without primer. MATERIALS AND METHODS: Two Initial Zirconia UHT (GC) sticks (1.8x1.8x5.0 mm) were bonded using four cements with and without their respective manufacturer's primer/adhesive (G-CEM ONE [GOne] and G-Multi Primer, GC; Panavia V5 [Pv5]), and Panavia SA Cement Universal [PSAu], and Clearfil Ceramic Plus, Kuraray Noritake; RelyX Universal (RXu) and Scotchbond Universal Plus [SBUp], 3M Oral Care). Specimens were trimmed to an hour-glass shaped specimen whose isthmus is circular in cross-section. After 1-week water storage, the specimens were either tested immediately (1-week µTBS) or first subjected to 50,000 thermocycles (50kTC-aged µTBS). The fracture mode was categorized as either adhesive interfacial failure, cohesive failure in composite cement, or mixed failure, followed by SEM fracture analysis of selected specimens. Data were analyzed using linear mixed-effects statistics (α = 0.05; variables: composite cement, primer/adhesive application, aging). RESULTS: The statistical analysis revealed no significant differences with aging (p = 0.3662). No significant difference in µTBS with/without primer and aging was recorded for GOne and PSAu. A significantly higher µTBS was recorded for Pv5 and RXu when applied with their respective primer/adhesive. Comparing the four composite cements when they were applied in the manner that resulted in their best performance, a significant difference in 50kTC-aged µTBS was found for PSAu compared to Pv5 and RXu. A significant decrease in µTBS upon 50kTC aging was only recorded for RXu in combination with SBUp. CONCLUSION: Adequate bonding to zirconia requires the functional monomer 10-MDP either contained in the composite cement, in which case a separate 10-MDP primer is no longer needed, or in the separately applied primer/adhesive.

Improvement of the selectivity of a molecularly imprinted polymer-based potentiometric sensor by using a specific functional monomer.

Potentiometric sensors based on the molecularly imprinted polymers (MIPs) as the receptors have been successfully developed for determination of various organic and biological species. However, these MIP receptors may suffer from problems of low selectivity. Especially, it would be difficult to distinguish the target analyte from its structurally similar interferents. In this work, we propose a novel strategy that using specific functional monomer to fabricate MIP with high selectivity towards the target molecule. The density functional theory calculations are used to investigate the interactions between the template and the functional monomer. The binding energy between the template and functional monomer can be used as the criterion for identifying the optimal monomer. As a proof-of-concept experiment, bisphenol A (BPA) is chosen as the template and the MIP is synthesized by the precipitation polymerization method using the specific allyl-ß-cyclodextrin (allyl-ß-CD) with high affinity towards BPA as the functional monomer. The high-affinity MIP is employed as the receptor for the construction of the potentiometric sensor. The proposed potentiometric sensor based on the MIP using allyl-ß-CD as the functional monomer shows an improved response performance in terms of selectivity and sensitivity compared to the conventional potentiometric sensor based on the MIP with the common monomer (i.e., methacrylic acid). This allyl-ß-CD MIP-based potentiometric sensor shows a detection limit of 0.29 µM for BPA, which is about one order of magnitude lower than that obtained by the conventional MIP-based potentiometric sensor. We believe that utilizing a functional monomer with specific recognition ability towards target in the fabrication of MIP could provide an appealing way to construct highly selective MIP-based electrochemical and optical sensors.

Construction of a Molecularly Imprinted Sensor Modified with Tea Branch Biochar and Its Rapid Detection of Norfloxacin Residues in Animal-Derived Foods.

Norfloxacin (NOR) is a common antibiotic used in humans and animals, and its high levels can cause intolerance or poisoning. Therefore, NOR levels in animal-derived foods must be monitored due to potential side effects and illegal use phenomena. This research centered on the development of an environmentally friendly electrochemical sensor for NOR detection. Potassium carbonate activated tea branch biochar (K-TBC) as an efficient use of waste was coated on the surface of glassy carbon electrode (GCE), and a molecular-imprinted polymer (MIP) layer was subsequently electropolymerized onto the modified electrode. NOR was used as template molecule and o-phenylenediamine (o-PD) and o-aminophenol (o-AP) were used as bifunctional monomers. The electrochemical sensor was built and its electrochemical behavior on NOR was investigated. The sensor demonstrated an excellent linear current response to NOR concentrations in the ranges of 0.1-0.5 nM and 0.5-100 nM under ideal experimental circumstances, with a detection limit of 0.028 nM (S/N = 3). With recoveries ranging from 85.90% to 101.71%, the designed sensor was effectively used to detect NOR in actual samples of milk, honey, and pork. Besides, the fabricated sensor had low price, short detection time, good selectivity and stability, which can provide a theoretical and practical basis for the actual monitoring of NOR residues.

Surface imprinting by using bi-functional monomers on spherical template magnetite for selective detection of levodopa in biological fluids.

The present work introduces an innovative biosensing platform for greatly sensitive determination of levodopa medicine. Initially, spherical magnetic (SM) nanoparticles were prepared by hydrothermal fabrication approach and used as a pattern to make spherical magnetic molecular imprinted polymer (SMMIP). Afterward, levodopa-molecularly imprinted layer was grown on the surface of the spherical magnetic pattern by electropolymerization with dopamine and resorcinol as bi-functional monomers and levodopa as a template molecule, which enhanced the specific recognition of the sensing platform to levodopa. The presence of SM nanoparticles could not only accelerate the mass transfer, the electron transport rate, and improve specific surface area of the electrode but also facilitate the recognition of the polymer, in this way increasing the current response and improving the performance of the biosensor. The superior sensing efficiency of the presented biosensor was confirmed based on the low limit of detection of 10 nmol L-1 which represented two linear ranges from 0.5 to 200 µmol L-1 and 200-1000 µmol L-1 for levodopa. More importantly, the practicability of the biosensor was proved by detecting levodopa in tablet, blood serum and plasma, implying that the sensing platform was suitable for monitoring levodopa in actual biological fluid and medicine.

Dual-Functional Monomer MIPs and Their Comparison to Mono-Functional Monomer MIPs for SPE and as Sensors.

A molecularly imprinted polymer (MIP) is a synthetic polymer that has characteristics such as natural receptors which are able to interact and bind to a specific molecule that is used as a template in the MIP polymerization process. MIPs have been widely developed because of the need for more selective, effective, and efficient methods for sample preparation, identification, isolation, and separation. The MIP compositions consist of a template, monomer, crosslinker, initiator, and porogenic solvent. Generally, MIPs are only synthesized using one type of monomer (mono-functional monomer); however, along with the development of MIPs, MIPs began to be synthesized using two types of monomers to improve the performance of MIPs. MIPs used for identification, separation, and molecular analysis have the most applications in solid-phase extraction (SPE) and as biochemical sensors. Until now, no review article has discussed the various studies carried out in recent years in relation to the synthesis of dual-functional monomer MIPs. This review is necessary, as an improvement in the performance of MIPs still needs to be explored, and a dual-functional monomer strategy is one way of overcoming the current performance limitations. In this review article, we discuss the techniques commonly used in the synthesis of dual-functional monomer MIPs, and the use of dual-functional monomer MIPs as sorbents in the MI-SPE method and as detection elements in biochemical sensors. The application of dual-functional monomer MIPs showed better selectivity and adsorption capacity in these areas when compared to mono-functional monomer MIPs. However, the combination of functional monomers must be selected properly, in order to achieve an effective synergistic effect and produce the ideal MIP characteristics. Therefore, studies regarding the synergistic effect of the MIP combination still need to be carried out to obtain MIPs with superior characteristics.

Biodegradable magnesium ion-doped silica-based molecularly imprinted nanoparticles for targeting tumor cells to drugs controlled release and recognition mechanism research.

Herein, we designed and constructed a novel biodegradable molecularly imprinted nanoparticles (Mg-SMSNs/DOX-Ce6 @MIPs) using a new degradable functional monomer prepared by glycerol and lactide, on magnesium ion-doped stellated mesoporous silica nanoparticles (Mg-SMSNs). These nanoparticles loaded with the anticancer drug doxorubicin (DOX) and chlorin e6 (Ce6) were used to target sialic acid (SA) overexpressed on the surface of tumor cells and release drugs in response to the tumor microenvironment. The molecularly imprinted layer avoided premature drug leakage, meanwhile, the large number of ester bonds contained in the functional monomers in the layer degraded by protonation in the tumor microenvironment to expose the drugs. Mg2+ doping in SMSNs enhanced the degradation performance in tumor microenvironment to achieve tumor-responsive drug release. The multifunctional monomers increased the interaction with SA, enhanced the binding force, and accurately targeted recognition was obtained. The recognition mechanism of Mg-SMSNs/DOX-Ce6 @MIPs to SA and drug release were investigated by model analysis. The cytotoxicity and cellular targeting of Mg-SMSNs/DOX-Ce6 @MIPs revealed that Mg-SMSNs/DOX-Ce6 @MIPs could specifically recognize SA to target MCF-7 tumor cells without interference. Under laser irradiation, Ce6 and DOX could achieve synergistic treatment to tumor cells. Mg-SMSNs/DOX-Ce6 @MIPs present good biological abilities in terms of active targeting, pH-responsiveness, antitumor efficiency and biocompatibility.

Effects of novel functionalized magnesium phosphate monomers on the flame retardancy and mechanical properties of polyethylene terephthalate copolymers.

In this study, inorganic magnesium hydroxide (MH) was modified by three phosphoric acids respectively to obtain three different novel functionalized monomers. The chemical structure and morphology of (Pn-MH) were analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Further, functional monomers were introduced into the PET main chain structure. A new type of high-performance co-polyesters was successfully prepared. The specific structure of P1-MH-PET was characterized by 1H NMR spectroscopy. Thermal stability of Pn-MH-PETs was analyzed by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The flame retardant properties were evaluated by limiting oxygen index (LOI), vertical combustion test (UL-94) and cone calorimeter. The results show that the thermal stability and flame retardant properties of 5%Pn-MH-PETs are greatly improved. Among them, the best performance is 5%P1-MH-PET, LOI is 32.5%, UL-94 test reached V-0 grade. Compared with neat PET, the peak heat release rate (PHRR), peak smoke release rate (PSPR), carbon dioxide release rate (CO2PR) and carbon monoxide release rate (COPR) decreased by 57.0%, 38.1%, 54.6% and 57.3%, respectively. Fortunately, the mechanical properties of 5%P3-MH-PET were also improved.

Fluorescent polydopamine based molecularly imprinted sensor for ultrafast and selective detection of p-nitrophenol in drinking water.

A highly effective fluorescent molecularly imprinted sensor (F-PDA-MIS) based on fluorescent polydopamine (F-PDA) was successfully synthesized for selective and ultrafast detection of p-nitrophenol (P-NP) in drinking water. F-PDA with abundant surface functional groups has been artfully modified to firstly serve as both fluorescent monomer and functional monomer in the synthesis of a uniform luminous F-PDA-MIS, which can greatly improve the detection efficiency. As expected, F-PDA-MIS had an obvious emission wavelength of 535 nm with the optimal excitation wavelength at 400 nm. Specially, F-PDA-MIS could detect P-NP in the range 100 to 1100 nM with much lower detection limit of 24.2 nM within 120 s compared with other conventional imprinted fluorescent sensors based on pure quantum dots (QDs) or dyes. This excellent test phenomenon is mainly ascribed to the rapid electron transfer between F-PDA and P-NP. Satisfactory recovery of 98.0-104% for mineral water and 98.6-106% for boiling water were obtained with relative standard deviations (RSDs) of 2.7-3.4% and 2.6-3.5% respectively. The detection reliability of F-PDA-MIS was verified by the comparison with high-performance liquid chromatography (HPLC-UV). Consequently, F-PDA as a fluorescence functional monomer has been shown to be a possible strategy to effectively improve the detection limit and shorten response time of the target determination in water..

Electrospun Fibers Derived from Peptide Coupled Amphiphilic Copolymers for Dorsal Root Ganglion (DRG) Outgrowth.

Developing scaffolds with appropriate mechanical/structural features as well as tunable bioactivities are indispensable in the field of tissue engineering. This study focused on one such attempt to electrospin the copolymer of L-lactic acid (L-LA) and functional monomer (3(S)- [(benzyloxycarbony)methyl]-1,4-dioxane-2,5-dione, BMD) with small peptide modifications for the purpose of neural tissue engineering. Scanning Electron Microscopy (SEM) micrographs showed fabricated electrospun copolymer as porous and uniform nanofibrous materials with diameter in the range of 800-1000 nm. In addition, the modified scaffolds displayed a lower contact angle than poly(L-lactide) (PLLA) indicating higher hydrophilicity. To further incorporate the bioactive functions, the nanofibers were chemically coupled with small peptide (isoleucine-lysine-valine-alanine-valine, IKVAV). The incorporation of IKVAV onto the electrospun fiber was confirmed by X-ray photoelectron spectroscopy (XPS) and such incorporation did not affect the surface morphology or fiber diameters. To demonstrate the potential of applying the designed scaffolds for nerve regeneration, dorsal root ganglion (DRG) neurons were cultured on the nanofibers to examine the impact on neurite outgrowth of DRGs. The results indicated that the fabricated nanofibrous matrix with small peptide might be a potential candidate for neural tissue engineering.

Constructing High-Recognition Protein-Imprinted Materials Using "Specially Designed" Block Macromolecular Chains as Functional Monomers and Crosslinkers.

The use of a macromolecularly functional monomer and crosslinker (MFM) to stabilize and imprint a template protein is a new method to construct high-recognition protein-imprinted materials. In this study, for the first time, a "specially designed" block MFM with both "functional capability" and "crosslinking capability" segments was synthesized via reversible addition-fragmentation chain-transfer polymerization and used to fabricate bovine serum albumin (BSA)-imprinted microspheres (SiO2@MPS@MIPs-MFM) by the surface imprinting strategy. Results from circular dichroic spectrum experiments reflected that the block MFM could maintain the natural form of BSA, whereas its corresponding and equivalent micromolecularly functional monomer (MIM) seriously destroyed the secondary structure of proteins. Batch rebinding experiments showed that the maximum adsorption capacity and imprinting factor of SiO2@MPS@MIPs-MFM reached 314.9 mg g-1 and 4.02, which were significantly superior to that of MIM-based imprinted materials. In addition, since the crosslinking capability segments in block MFM involved zwitterionic functional groups with a protein-repelling effect, SiO2@MPS@MIPs-MFM showed better specific rebinding ability than the imprinted material prepared by MFM without this component. Besides, scanning electron microscopy and transmission electron microscopy images showed that the shell thickness of SiO2@MPS@MIPs-MFM was approximately 15 nm, and such a thin imprinted layer ensured its rapid adsorption equilibrium (120 min). As a result, SiO2@MPS@MIPs-MFM revealed fantastic selectivity and recognition ability in a mixed protein solution and could efficiently extract BSA from biological samples of bovine calf serum. The proposal of block MFM enriched the options and designability of monomers in protein imprinting technology, thereby laying a foundation for developing high-performance protein-imprinted materials.

Synergetic Effect of Dual Functional Monomers in Molecularly Imprinted Polymer Preparation for Selective Solid Phase Extraction of Ciprofloxacin.

BACKGROUND: Ciprofloxacin (CIP), an important broad-spectrum fluoroquinolone antibiotic, was often used as a template molecule for the preparation of imprinted materials. In this study, methacrylic acid and 2-vinylpyridine were employed for the first time as dual functional monomers for synthesizing ciprofloxacin imprinted polymers. METHODS: The chemical and physicochemical properties of synthesized polymers were characterized using Fourier transform-infrared spectroscopy, thermogravimetric analysis-differential scanning calorimetry, scanning electron microscopy, and nitrogen adsorption-desorption isotherm. The adsorption properties of ciprofloxacin onto synthesized polymers were determined by batch experiments. The extraction performances were studied using the solid phase extraction and HPLC-UV method. RESULTS: The molecularly imprinted polymer synthesized with dual functional monomers showed a higher adsorption capacity and selectivity toward the template molecule. The adsorbed amounts of ciprofloxacin onto the imprinted and non-imprinted polymer were 2.40 and 1.45 mg g-1, respectively. Furthermore, the imprinted polymers were employed as a selective adsorbent for the solid phase extraction of ciprofloxacin in aqueous solutions with the recovery of 105% and relative standard deviation of 7.9%. This work provides an alternative approach for designing a new adsorbent with high adsorption capacity and good extraction performance for highly polar template molecules.

Fluorescence Sensing with Molecularly Imprinted Polymer-Capped Quantum Dots.

Procedures for the design of a fluorescence sensor based on molecularly imprinted polymer-capped quantum dots (MIP@QDs) together with the synthesis of quantum dots and MIP@QDS are described. Spherical and monodispersed nanoparticles are suitable for fluorescence sensing of an analyte such as pharmaceuticals and polycyclic aromatic hydrocarbons (PAHs). In addition, excellent optical properties, higher quantum yield, and photoluminescence efficiency as well as easy detection of emission spectra are distinctive advantages of quantum dots as fluorescence sensors. Optimization of different variables and analytical applications of the sensor are also presented, which are of value for fluorescence sensing.

Evaluation of the effects of three pretreatment conditioners and a surface preparation system on the bonding durability of composite resin adhesive to a gold alloy.

This study aimed to evaluate the effect of three pretreatment conditioners and surface preparations on a composite resin adhesive for a gold alloy. Cast disk specimens were made and bonded with RelyX Unicem luting agent under six surface conditions: 1) polished with No.600 carbide paper, 2) air-abraded with alumina, 3) Alloy Primer metal conditioner was applied after alumina-abrasion, 4) Monobond Plus multipurpose conditioner was applied after alumina-abrasion, 5) M. L. Primer metal conditioner was applied after alumina-abrasion, and 6) Rocatec multipurpose silica-coating system was applied. The bond strengths were determined before and after thermocycling (50,000 cycles). The bond strengths of the alumina-abrasion group were significantly decreased after thermocycling. The Rocatec and M. L. Primer exhibited higher bond strengths than other treatments. The application of metal conditioners and multipurpose surface preparations was recommended for improved bonding between the evaluated adhesive resin and gold alloy.

Effects of Copper Surface Oxidation and Reduction on Shear-Bond Strength Using Functional Monomers.

This study was conducted to clarify the influence of the copper surface oxidation and reduction on the shear-bond strength with functional monomers. Unheated copper specimens (UH; n = 88) were wet-ground. Three-quarters of the UH were then heated (HT). Two-thirds of the HT was then immersed in a hydrochloric acid solution (AC). Half of the AC was then reheated (RH). Each group was further divided into two groups (n = 11), which were primed by either 6-methacryloyloxyhexyl 2-thiouracil-5-carboxylate (MTU-6) or 10-methacryloyloxydecyl dihydrogen phosphate (MDP). The shear-bond strength tests were used for bonding with an acrylic resin. The surface roughness values and chemical states of the four groups were analyzed using a confocal scanning laser microscope and X-ray photoelectron spectroscopy (XPS). The shear-bond strengths of HT and RH were the lowest in the MTU-6-primed groups. The result of AC was significantly lower than others in the MDP-primed groups. The XPS results showed that the surfaces of UH and AC consisted of Cu2O and Cu. The surface changed to CuO upon heating. The presence or absence of copper-oxide films showed the opposite trends in the effectiveness of MTU-6 and MDP to improve bond strength. The results could elucidate the effects of functional monomers on copper-oxide films.

Preparation of monodisperse, restricted-access, media-molecularly imprinted polymers using bi-functional monomers for solid-phase extraction of sarafloxacin from complex samples.

Monodisperse restricted-access media bi-functional monomers with molecularly imprinted polymers (RAM-MIPs) were constructed using surface-initiated atom transfer radical polymerization. They were used as solid-phase extraction (SPE) adsorbents to enrich sarafloxacin (SAR) residues from egg samples, and influences on their performance were investigated. Optimum synthesis of RAM-MIPs was achieved by combining a bi-functional monomer (4-vinylpyridine-co-methacrylic acid, 1:3) with an 8:1:32:8 ratio of a template molecule, cross-linker, and restricted-access functional monomer. The SAR imprinting factor of RAM-MIPs was 6.05 and the selectivity coefficient between SAR and other fluoroquinolones was 1.86-2.64. Compared with traditional MIPs, the RAM-MIPs showed better SAR enrichment and selectivity during extraction of a complex protein-containing solution. Empty SPE cartridges were filled with RAM-MIP microspheres as SPE adsorbents. The limit of quantitation for SAR was 4.23 ng g-1 (signal-to-noise ratio = 10) and the mean SAR recovery from spiked egg samples was 94.0-101.3%. Intra-day and inter-day relative standard deviations were 1.1-9% and 1.5-3.3%, respectively.

Preparation and characterization of a chiral molecularly imprinted polymer with a novel functional monomer for controlled release of S-sulpiride.

A novel molecularly imprinted polymer (MIP) with chiral recognition affinity to S-sulpiride (S-SUL) enantiomer was prepared by using newly synthesized N-acryloyl-tryptophan (ATrp) as function monomer, S-SUL as the template molecule, and ethyleneglycol dimethacrylate (EGDMA) as the cross linker. Under the optimized synthesis conditions, the MIP was synthesized by bulk polymerization according to the molar ratio of 1:4 of S-SUL to ATrp, and structurally characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and laser particle analysis. The results illustrated that the MIP offered uniform, loose and porous structure. The adsorption performance of the MIP was evaluated by the isotherm and kinetic models, and the adsorption isotherm conformed to the Freundlich model. The maximum adsorption capacity, selectivity factor and enantioselectivity coefficient to S-SUL were respectively 226.2389 µmol/g, 2.34 and 11.66. Based on the chiral recognition specificity, the drug release experiments demonstrated that the MIP as controlled and sustained release carrier could inhibit the release rate of S-enantiomer compared to the tablet without the MIP, exhibiting the potential of the MIP synthesized in chiral drug delivery.

4-(6-Aminohexyl) amino-4-oxo-2-butenoic acid as a novel hydrophilic monomer for synthesis of cellulose-based superabsorbents with high water absorption capacity.

An efficient cellulosic superabsorbent based on a novel functional monomer 4-(6-aminohexyl) amino-4-oxo-2-butenoic acid (AHOB) and acrylic acid was successfully synthesized by free-radical solution polymerization and the effect of the AHOB monomer on the structure, morphology, thermal behavior and viscoelastic features of this superabsorbent was investigated by FTIR, SEM, TGA and rheology methods. Also, the influence of this monomer on the water absorption capacity in various pH and different saline solutions, kinetic behavior, water retention capacity and reusability of the superabsorbent was perused. The results of these experiments confirmed the significant role of the AHOB monomer in improving the properties of the superabsorbent. The excellent absorbency (800.37 g/g in distilled water and 78.02 g/g in 1 wt.% NaCl solution) and high water retention capacity of the prepared superabsorbent showed that it can be used as an efficient water-saving material for agricultural applications.

Norepinephrine as new functional monomer for molecular imprinting: An applicative study for the optical sensing of cardiac biomarkers.

The continuous research for alternatives to antibody-based detection drove, in the last decades, the development of numerous strategies. Molecularly imprinted polymers (MIPs) emerged thanks to the low-cost and long-term stability features, where the choice of natural functional monomer(s) represents the key step for efficient imprinting of biomolecules. The chemical structure of dopamine (DA), one of the most used natural functional monomers, provided the inspiration for this work. We wondered why norepinephrine (NE) that differs from dopamine only for an additional hydroxyl group was not investigated at all in biosensing applications. In fact, there is only one paper exploiting polynorepinephrine (PNE) in molecular recognition applications, taking advantage of molecular imprinting, but not for biosensing purposes. In contrast, hundreds of papers describe polydopamine-based sensors. Therefore, we firstly investigated how the additional hydroxyl group of NE could affect the properties of the resulting polymer, and how these properties could be exploited for biosensing applications. The results highlighted the reduced non-specific adsorption of proteins onto PNE with respect to dopamine polymer. Furthermore, as a case study, we successfully developed a PNE-based imprinted biosensor for the early detection of Troponin I, a crucial biomarker for heart failure, by coupling the MIP biosensor with surface plasmon resonance (SPR) detection. The results indicate the feasible use of imprinted PNE as synthetic receptor for biomolecules, opening new perspectives for this biopolymer, so far not considered, and encouraging further investigations on its potential application in biosensing.