Facile Preparation of Core−Shell Type Molecularly Imprinted Particles: Molecular Imprinting into Aromatic Polyimide Coated on Silica Spheres

Molecularly Imprinted Chalcone-Branched Polyimide-Based Chemosensors with Stripe Nanopatterns for the Detection of Melittin

In this study, a chalcone-branched polyimide (CB-PI) was synthesized by the Steglich esterification reaction for selective recognition of the toxic peptide melittin (MEL). MEL was immobilized on a nanopatterned poly(dimethylsiloxane) (PDMS) mold using a conventional surface modification technique to increase binding sites. A stripe-nanopatterned thin CB-PI film was formed on a quartz crystal (QC) substrate by simultaneously performing microcontact printing and ultraviolet (UV) light dimerization using a MEL-immobilized mold. The surface morphology changes and dimensions of the molecularly imprinted polymer (MIP) films with stripe nanopatterns (S-MIP) were analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The sensing signals (Δf and Qe) of the S-MIP sensor were investigated upon adsorption in a 100-μL dilute plasma solution containing 30 μg/mL MEL, and its reproducibility, reuse, stability, and durability were investigated. The S-MIP sensor showed high sensitivity (5.49 mL/mg) and coefficient of determination (R2 = 0.999), and the detection limit (LOD) and the quantification limit (LOQ) were determined as 0.3 and 1.1 μg/mL, respectively. In addition, the selectivity coefficients (k*) calculated from the selectivity tests were 2.7-5.7, 2.1-4.3, and 2.8-4.6 for bovine serum albumin (BSA), immunoglobulin G (IgG), and apamin (APA), respectively. Our results indicate that the nanopatterned MIP sensors based on CB-PI demonstrate great potential as a sensing tool for the quantitative analysis of biomolecules.

One-step synthesis and magnetic properties of Ni-Fe3O4@PI core–shell composite microspheres

Nickel(Ni)-iron(III) oxide(Fe3O4)@polyimide (PI) composite microspheres were successfully prepared from poly(amic acid) triethylammonium salts and a mixture of Fe(III) and Ni(II) via a facile one-step solvothermal process. Furthermore, the formation mechanism of the composite microspheres has been investigated. The morphology and the structure of the samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and infrared spectroscopy, respectively. It was determined that PI could be successfully coated on the surface of the magnetic microspheres. Based on the results obtained from thermo-gravimetric analysis and vibrating sample magnetometer curves, it was found that the composite microspheres exhibit an excellent thermal stability. The prepared sample, coined NiFe@PI-4, with higher weight content of iron particles in the polymer matrix, showed improved magnetic properties (saturation magnetization = 57.1 emu/g) due to the high saturation magnetization of Fe3O4 and excellent dispersion effects of polyethylene glycol on the nanoparticles in solution.

Inorganic/polymer hybrid nanoparticles for sensing applications

This paper reviews a wide set of sensing applications based on the special properties associated with inorganic/polymer composite nanoparticles. We first describe optical sensing applications performed with hybrid nanoparticles and hybrid microgels with special emphasis on photoluminescence detection and imaging. Analyte detection with molecularly imprinted polymers and HPLC-based sensing using hybrid nanoparticles as stationary phase is also summarized. The final part is devoted to the study of ultra-sensitive molecule detection by surface-enhanced Raman spectroscopy using core-shell hybrid materials composed of noble metal nanoparticles and cross-linked polymers.

Selective adsorption of elastase by surface molecular imprinting materials prepared with novel monomer

A new functional monomer with diol groups was synthesized and applied to fabricate surface molecular imprinting polymers (SMIPs) microspheres for selective adsorption of elastase.

Effect of Trolamine and Dibutyltindilaurate on the Structure and Properties of Polyurethane-imide Foams

Polyurethane-imide foams are prepared from polyphenyl polymethylene polyisocyanates, pyromellitic dianhydride and castor oil in presence of trolamine and dibutyltindilaurate catalysts. FTIR spectra proves the successful preparation of polyurethane-imide foams in prepolymer method. The investigation on catalytic mechanism shows that trolamine and dibutyltindilaurate are effective in promoting blowing and gelling reaction, respectively, so trolamine and dibutyltindilaurate are identified to be blowing catalyst and gelling catalyst, respectively. With the fixed amount of trolamine, the density and compressive strength of the resulting foams are enhanced with the increase of dibutyltindilaurate, but average cellular diameter and open cell contents are reduced. Similarly, with the fixed amount of dibutyltindilaurate, open cell contents of the resulting foams are enhanced with the increase of trolamine, while the density, compressive strength and average cellular diameter decreased. Thus PUIFs with variable properties can be prepared through changing the kind and ratio of mixed catalysts.

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011

Herein, we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004-2011. In total, 3779 references to the original papers, reviews, edited volumes and monographs from this period are included, along with recently identified uncited materials from prior to 2004, which were omitted in the first instalment of this series covering the years 1930-2003. In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by sections describing fundamental aspects of molecular imprinting including the development of novel polymer formats. Thereafter, literature describing efforts to apply these polymeric materials to a range of application areas is presented. Current trends and areas of rapid development are discussed.

Fabrication of a new electrochemical sensor based on a new nano-molecularly imprinted polymer for highly selective and sensitive determination of tramadol in human urine samples

A new nano-molecularly imprinted polymer bead was synthesized and applied to the fabrication of a chemically modified carbon paste electrode. Nano-molecularly imprinted polymer with molecular recognition capacity was made-up by using SiO2@Fe3O4 as the core and the supporting material. The electrode was applied to the simple, rapid, highly selective and sensitive determination of tramadol using square wave voltammetry. The molecularly imprinted polymer and multi-walled carbon nanotubes modified carbon paste electrode was prepared by incorporating the synthesized nano-MIP and multi-walled carbon nanotubes in carbon paste electrode. The limit of detection and the linear range were found to be 0.004 and 0.01 to 20 μmol L(-1) of tramadol, respectively. The effects of potentially interfering substances on the determination of this compound were investigated. And it was found that the electrode is highly selective. The proposed chemically modified carbon paste electrode was used for the determination of tramadol in infected and healthy human urine and pharmaceutical samples.

Use of templates to fabricate nanoscale spherical structures for defined architectural control

Architectural design of biomaterial structures is essential to reach the full potential of the materials' chemical and biological properties. Clinically, these properties depend on the targeted applications of delivery, such as tissue regeneration, imaging, or cancer. To get an efficient material for biological applications, key properties are needed, such as degradability, low toxicity, cell specificity, relative efficiency, and capability of delivering multiple molecules. In recent years, significant progress has been made through either the design of the material itself (synthetic or natural polymers, dendrimers, crosslinking) or the fabrication technique (nozzle reactor, emulsion, and template). The combination of these materials and techniques results in a large variety of biomaterials that have varied shape and physico-chemical and biological properties. Nevertheless, these inherent properties are not sufficient and interest in discovering and developing new techniques that present these biomaterials in different light is now under focus. A useful strategy to prepare biomaterials with unique and novel architectures is through the use of templates that have defined geometrical features. This holds great promise, especially for the development of hollow structures, such as spheres. The nanoscale structural design of biomaterials via the use of templates and their potential clinical applications are discussed. In addition, the conceptual hurdles that must be overcome to produce applications that are clinically relevant are examined.

Monodispersed, molecularly imprinted polymers for cinchonidine by precipitation polymerization

Three monodispersed, molecularly imprinted polymers (MIPs) for cinchonidine (CD) have been synthesized by precipitation polymerization. MIP1 was prepared using methacrylic acid (MAA) as a functional monomer and divinylbenzene (DVB) as a cross-linker and MIP2 was prepared with further addition of 2-hydroxyethyl methacrylate (HEMA) as a co-monomer. For the preparation of MIP3, core-shell type MIP, monodispersed DVB homopolymers, which are prepared by precipitation polymerization, were used as a core and CD-imprinted MAA-DVB copolymer phases were coated onto the core. Three MIPs synthesized gave monodispersed, spherical beads in micrometer sizes. The binding characteristics and molecular recognition properties of MIP1-3 were examined by Scatchard analysis and chromatographic studies. The association constant of CD with MIP1 was the highest among MIPs prepared, while that with MIP3 was the lowest. The template molecule, CD, was more retained than its stereoisomer, cinchonine, on the three MIPs, and the stereoseparation factor of 38 was obtained with MIP3.

Ultrathin molecularly imprinted polymer sensors employing enhanced transmission surface plasmon resonance spectroscopy

An ultrathin novel nanosensor (31.5 +/- 4.1 nm thick in the absence of analytes), employing a molecularly imprinted polymer as a recognition element for cholesterol and gold nanoparticle enhanced transmission surface plasmon resonance spectroscopy for detection, was constructed.