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In this work, molecularly imprinted electrospun chromogenic membrane(MIP-ECM) was synthesized using P-Hydroxybenzene propanoic acid as imitate template molecule and Poly (vinyl alcohol)(PVA) as substrate. Ninhydrin is used as chromogenic agent for visualizing detection of target molecule l-tyrosine(Tyr). The results showed that molecularly imprinted membrane exhibited selectivity and specific adsorption capacity for l-tyrosine. The influences of environmental factors, such as reaction temperature, the amount of ninhydrin and elution time, on chromogenic properties were examined by SEM and optical microscope. Gray value analysis is proceeded by software Image J. Due to the facilitate preparation and intuitive visualization, the proposed method was a promising candidate for selective recognition of bio-generated acid and amino molecules., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Bovine serum albumin (BSA) imprinted polyampholyte hydrogels (PAHs) were prepared by free radical polymerization using acrylamide (Am) as structural monomer, N-isopropylacrylamide (NIPAm), [2-(methacryloyloxy)ethyl]trimethylammonium chloride (DMC) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) as functional monomers and N,N'-methylenebisacrylamide (MBA) as crosslinker in aqueous solution. The morphology of imprinted hydrogels and non-imprinted hydrogels were characterized by scanning electron microscope (SEM). The adsorption and recognition properties were evaluated as functions of Am monomer concentration, NIPAm/Am molar ratio, crosslinking structure and charge density ratio etc. The adsorption capacity and association constant of specific interaction between hydrogel and template protein were analyzed by Langmuir isotherm model and Freundlich model. The fitting experimental data suggested that this adsorption was better described as a monolayer adsorption. The specific adsorption on hydrogel with different crosslinking structure was investigated by selective binding BSA from single solution and binary mixture solution. The charge density ratio in molecular imprinting hydrogel had obvious influence for protein adsorption and recognition. The resultant of regeneration tests showed that elution had large impact on deterioration of the imprinting structure., (Copyright © 2018 Elsevier B.V. All rights reserved.)

An imprinted electrospun fiber membrane was developed for the detection of volatile organic acids, which are key components of human body odor. In this study, hexanoic acid (HA) was selected as the target, polymethyl methacrylate (PMMA) was used as the substrate, and colorimetric detection of HA was achieved by a bromocresol purple (BCP) chromogenic agent. The results showed that the morphology of the fiber membrane was uniform and continuous, and it showed excellent selectivity and specificity to HA. Photographs of the color changes before and after fiber membrane adsorption were recorded by a camera and quantified by ImageJ software by the difference in gray value (ΔGray). This method is simple, intuitive, and low cost and has great potential for application in human odor analysis.

Combining molecular imprinting technology with electrostatic spinning technology, a molecularly imprinted nanofiber membrane material with memory and recognition of specific imprinted molecules is thus produced. It has the advantages of high efficiency, reusability, easy amplification, and simple operation. In this study, alkane molecularly imprinted nanofibrous membranes are prepared as a carrier for immobilize Bacillus cereus LY‐1 for the degradation of diesel in oil–water system. The adsorption capacity of the molecularly imprinted material for diesel oil with n‐decyl alcohol as the template molecule reach 120.25 mg g−1, the adsorption capacity of alkane molecularly imprint nanofiber membrane prepared using polyvinyl alcohol (PVA) as the membrane substrate material is 41.37 mg g−1. After 4 days, the immobilized LY‐1 cells eliminate roughly 80.7% of the diesel at a starting concentration of 3 g L−1. The results show that imprinted structures in MINM enhance degradation by loaded microorganisms. [ABSTRACT FROM AUTHOR]

In this work, we have developed a double‐layer nanofiber membrane (NFM) with high selectivity based on molecular imprinting technique by electrospinning methods and applied it in recognizing putrescine. Poly(vinyl alcohol) (PVA) was used as spinning solution, 1,4‐butylene glycol as the imitate template, and ninhydrin as chromogenic agent. The adsorption of the putrescine is corresponded to purple‐color stains on the NFM, which is digitizing intuitively by the ImageJ software. By quantifying the gray value of the stains on the NFM, its imprinting efficiency (IE) is estimated. The adsorption performance of the double‐layer molecular imprinted NFM was studied in detail, showing higher adsorption capacity (71.912 mg mL−1), shorter adsorption equilibrium time of 40 min and higher selectivity to putrescine than our previous works. Furthermore, the material showed remarkable selectivity for putrescine with respect to other three kinds of aliphatic amine in similar molecular structure. The selectivity coefficient (α) of putrescine against cadaverine, spermine, and spermidine are calculated to be 1.734, 2.224, and 2.576, respectively. In addition, since PVA is a water‐soluble material, the NFM is not reusable. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48932. [ABSTRACT FROM AUTHOR]

This work is an exploration into visualizing measurement of putrescine specific adsorption by photographing colorized molecule imprinting chromogenic hydrogel. Membranes are prepared with imitate templates 1,4-butylene glycol, adipic acid or succinic acid, respectively and ninhydrin is used as chromogenic agent for target molecule putrescine. The adsorbing concentration on MIP is reflected in the form of visible violet-colored stain differed in shape and shade, which are recorded by hyper spectral camera and proceeded into intuitive 3D isohypse surfaces plot. By quantifying the height of surface peaks, imprinting efficiency is estimated in accordance with polyvinyl alcohol concentration and crosslinking degree. The imprinting efficiency of three imitate molecule templates is also discussed. [ABSTRACT FROM AUTHOR]

Polyurethane grafted calcium alginate hydrogel microspheres intended for bovine serum albumin imprinting were prepared and characterized. The grafting modification was performed prior to the assembling of protein template with hydrogel, which was advantageous to maintain protein conformation and construct more accessible imprinted sites. It was found that the imprinted hydrogel had higher affinity to template molecules after modification. Investigations of grafting ratio influence on specific rebinding and competitive properties indicated that grafted side chains were beneficial to the selective recognition of protein. [ABSTRACT FROM AUTHOR]

Electrospinning is an important tool for generating continuous fibers with large surface area and high pore ratio. The combination of nanofiber membrane and molecular imprinting can effectively measure specific adsorption of putrescine with coloring procedure. In this work, molecularly imprinted electrospun chromogenic membrane was synthesized with 1,4‐butanediol (BDO) as imitate template. Poly(vinyl alcohol) (PVA) is used as spinning solution and ninhydrin as chromogenic agent for visualizing detection of target molecular putrescine. The adsorption concentration on molecularly imprinted polymer is illustrated by blue‐purple colored stains and recorded by interactive three‐dimensional surface plot of ImageJ. The results indicated that a uniform and bead‐free PVA nanofiber was obtained using 10% (w/w) PVA solution, 15 kV voltage, 15 cm spinning distance, and 600 rpm roller speed. Also, the adsorption performance of molecular imprinting chromogenic membrane was investigated in detail, showing a higher adsorption capacity of 33.16 μg cm−2 and maximum imprinting efficiency of 2.30 under the best recognition conditions of 315 μL ninhydrin, 0.25% (w/w) BDO, and 0.4 cm sensing distance, as well as a short adsorption equilibrium time of 40 min. In addition, three amine competitors were discussed to reveal the better selectivity and higher specific recognition ability in the imprinted membrane. HIGHLIGHTS: The molecular imprinting and coloring structure is constructed in nanofiber membrane with an enhanced specific surface area.The adsorption on imprinted membrane is visualized by chromogenic reaction between putrescine and ninhydrin to form a three‐dimensional interactive surface proceeded using the ImageJ software.The imprinted nanofiber membrane with large area and high pore ratio is applied in detecting target in trace concentration within shortened time. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48186. [ABSTRACT FROM AUTHOR]