Computational simulation and preparation of fluorescent magnetic molecularly imprinted silica nanospheres for ciprofloxacin or norfloxacin sensing

Application of molecular imprinting technology based on new nanomaterials in adsorption and detection of fluoroquinolones

Irrational use of fluoroquinolones (FQs) can lead to allergic reactions, adverse reactions to the heart and damage of the liver; thus, it is of great significance to establish rapid, sensitive and accurate detection methods for FQs. Molecularly imprinted polymers (MIPs) with specific structures synthesized by molecular imprinting technology (MIT) are widely used for the detection of FQs due to their high specificity, high sensitivity and stable performance. Recently, new functional nanomaterials with different morphologies and sizes, which can provide rich sites for surface chemical reactions, have attracted more and more attention of the researchers. Thus, the application status and development prospects of MIT based on new nanomaterials in the adsorption and detection of FQs were summarized in this study, providing a theoretical basis and technical guarantee for the development of new and efficient food safety analysis strategies based on MIPs.

Dummy molecularly imprinted solid-phase extraction-SERS determination of AFB1 in peanut

As a class I carcinogen, aflatoxin B1 (AFB1) contamination in foods and feeds accounts for 75 % of the total mycotoxin contamination. In this work, a simple and reliable surface-enhanced Raman spectroscopy (SERS) method for sensitive and selective detection of AFB1 in peanut samples integrated with dummy molecularly imprinted polymers (DMIPs) is developed. N-isopropylacrylamide (NIPAM) and 7-ethoxycoumarin (7-EOC) are chosen as monomer and dummy template, respectively and their ratio was screened through molecular design in both of kinetic and static adsorption views to form the optimal DMIPs. As-prepared dummy molecularly imprinted solid-phase extraction (DMISPE) could selectively enrich AFB1 from peanut samples. Finally, a liquid-liquid interface self-assembly constructed thioctic acid-decorated AgNPs monolayer film (TA-AgNPs MF) as a SERS-active substrate is employed to determine the amount of AFB1 eluted from DMISPE. SERS assay shows high detection sensitivity for AFB1 in peanut samples with limit of detection of 0.1 μg L^-1 and a linear concentration relationship range from 0.1 to 10 μg L^-1.

The Use of Computational Methods for the Development of Molecularly Imprinted Polymers

Recent years have witnessed a dramatic increase in the use of theoretical and computational approaches in the study and development of molecular imprinting systems. These tools are being used to either improve understanding of the mechanisms underlying the function of molecular imprinting systems or for the design of new systems. Here, we present an overview of the literature describing the application of theoretical and computational techniques to the different stages of the molecular imprinting process (pre-polymerization mixture, polymerization process and ligand-molecularly imprinted polymer rebinding), along with an analysis of trends within and the current status of this aspect of the molecular imprinting field.

A Review on Molecularly Imprinted Polymers Preparation by Computational Simulation-Aided Methods

Molecularly imprinted polymers (MIPs) are obtained by initiating the polymerization of functional monomers surrounding a template molecule in the presence of crosslinkers and porogens. The best adsorption performance can be achieved by optimizing the polymerization conditions, but this process is time consuming and labor-intensive. Theoretical calculation based on calculation simulations and intermolecular forces is an effective method to solve this problem because it is convenient, versatile, environmentally friendly, and inexpensive. In this article, computational simulation modeling methods are introduced, and the theoretical optimization methods of various molecular simulation calculation software for preparing molecularly imprinted polymers are proposed. The progress in research on and application of molecularly imprinted polymers prepared by computational simulations and computational software in the past two decades are reviewed. Computer molecular simulation methods, including molecular mechanics, molecular dynamics and quantum mechanics, are universally applicable for the MIP-based materials. Furthermore, the new role of computational simulation in the future development of molecular imprinting technology is explored.

A chitosan gold nanoparticles molecularly imprinted polymer based ciprofloxacin sensor

In this work, we present a novel study on the development of an electrochemical biomimetic sensor to detect the ciprofloxacin (CIP) antibiotic. A chitosan gold nanoparticles decorated molecularly imprinted polymer (Ch-AuMIP) was used to modify the glassy carbon electrode (GCE) for preparation of the sensor. The Ch-AuMIP was characterized to understand various properties like chemical composition, morphology, roughness, and conduction using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and cyclic voltammetry (CV) respectively. Several experimental conditions affecting the Ch-AuMIP/GCE sensor such as the CIP removal agent, the extraction time, the volume of Ch-AuMIP drop-cast onto GCE and the rebinding time were studied and optimized. The Ch-AuMIP sensor sensitivity was studied in the concentration range of 1-100 μmol L-1 exhibiting a limit of detection of 210 nmol L-1. The synergistic combination of Au nanoparticles and Ch-MIP helps detect the CIP antibiotic with good sensitivity and selectivity, respectively. We investigated the selectivity aspect by using some possible interfering species and the developed sensing system showed good selectivity for CIP with a 66% response compared to the other compounds (≤45% response). The proposed sensing strategy showed its applicability for successful detection of CIP in real samples like tap water, mineral water, milk, and pharmaceutical formulation. The developed sensor showed good selectivity towards CIP even among the analogue molecules of Norfloxacin (NFX) and Ofloxacin (OFX). The developed sensor was successfully applied to determine the CIP in different samples with a satisfactory recovery in the range of 94 to 106%.

Dual roles of 3-aminopropyltriethoxysilane in preparing molecularly imprinted silica particles for specific recognition of target molecules

3-Aminopropyltriethoxysilane (APTES) is a silane widely used to supply amino groups for further modifications on various materials, but it is less studied as a catalyst to catalyze sol–gel silica polymerization. Here, by using APTES as the catalyst instead of the conventional basic catalysts, a novel strategy was developed to prepare silica-based molecularly imprinted polymers (MIPs). Meanwhile, APTES was employed as the functional monomer to create imprinted nanocavities for specific recognition of target molecules. The as-synthesized MIP exhibited ultra-high recognition capability due to the elimination of the detrimental effect on the imprinting performance caused by the additional catalysts. The preparation process, specificity, pH effect, binding capacity and affinity of the MIP were studied in detail. The MIP microparticles could be packed into a solid phase extraction column for removing the target molecule in water efficiently, and the molecule could easily be enriched by 40 times. The interaction of the functional monomer and template was studied by the calculation method, giving a more clear understanding of the recognition behaviours of the imprinted polymers. The strategy could be extended not only to prepare highly specific MIPs for other small phosphoric molecules, but also for biomolecules e.g. phosphorylated peptides or proteins.

A novel strategy was developed for preparing highly selective molecularly imprinted polymers using 3-aminopropyltriethoxysilane as both a functional monomer and catalyst.

Determination of norfloxacin in urine and pharmaceutical samples using terbium doped zinc sulphide nanomaterials-sensitized fluorescence method

Highly crystalline polyethylene glycol (PEG) coated Tb³⁺ doped ZnS nanoparticles have been synthesized and successfully used for norfloxacin sensing. The crystallographic and morphological analyses of PEG coated Tb³⁺ doped ZnS nanoparticles were performed by X-ray diffraction and Transmission electron microscopy, respectively. The confirmation of Tb³⁺ doping in ZnS host matrix was done by emission spectroscopy and energy dispersive X-ray spectroscopy. Further, the interaction of norfloxacin with PEG coated Tb³⁺ doped ZnS nanomaterials was confirmed by optical analysis: spectrophotometrically and spectrofluorimetrically. Norfloxacin sensing was measured by luminescence intensity which increased with increase in concentration of norfloxacin in range from 2.0 × 10^-9-8.0 × 10^-7 mol L^-1, with its correlation coefficient 0.9991. The detection limit of proposed method was 0.05 × 10^-9 mol L^-1. The developed luminescence method was successfully applied for the determination of norfloxacin using PEG coated Tb³⁺ doped ZnS nanoparticles in urine and pharmaceutical samples.

MIRATE: MIps RATional dEsign Science Gateway

Molecularly imprinted polymers (MIPs) are high affinity robust synthetic receptors, which can be optimally synthesized and manufactured more economically than their biological equivalents (i.e. antibody). In MIPs production, rational design based on molecular modeling is a commonly employed technique. This mostly aids in (i) virtual screening of functional monomers (FMs), (ii) optimization of monomer-template ratio, and (iii) selectivity analysis. We present MIRATE, an integrated science gateway for the intelligent design of MIPs. By combining and adapting multiple state-of-the-art bioinformatics tools into automated and innovative pipelines, MIRATE guides the user through the entire process of MIPs' design. The platform allows the user to fully customize each stage involved in the MIPs' design, with the main goal to support the synthesis in the wet-laboratory. Availability: MIRATE is freely accessible with no login requirement at http://mirate.di.univr.it/. All major browsers are supported.

Imprinted Oxide and MIP/Oxide Hybrid Nanomaterials for Chemical Sensors †

The oxides of transition, post-transition and rare-earth metals have a long history of robust and fast responsive recognition elements for electronic, optical, and gravimetric devices. A wide range of applications successfully utilized pristine or doped metal oxides and polymer-oxide hybrids as nanostructured recognition elements for the detection of biologically relevant molecules, harmful organic substances, and drugs as well as for the investigative process control applications. An overview of the selected recognition applications of molecularly imprinted sol-gel phases, metal oxides and hybrid nanomaterials composed of molecularly imprinted polymers (MIP) and metal oxides is presented herein. The formation and fabrication processes for imprinted sol-gel layers, metal oxides, MIP-coated oxide nanoparticles and other MIP/oxide nanohybrids are discussed along with their applications in monitoring bioorganic analytes and processes. The sensor characteristics such as dynamic detection range and limit of detection are compared as the performance criterion and the miniaturization and commercialization possibilities are critically discussed.

A simple extraction method for norfloxacin from pharmaceutical wastewater with a magnetic core–shell molecularly imprinted polymer with the aid of computer simulation

The best functional monomer was screened using computer simulation. Interaction mechanism between MMIP and norfloxacin was explained using pH optimization and zeta potential detection.