Synthesis of Molecularly Imprinted Polymers for Nevirapine by Dummy Template Imprinting Approach

Preparation and optimization of dummy molecularly imprinted polymer-based solid-phase extraction system for selective enrichment of p-toluene sulfonate esters genotoxic impurities

Sulfonate esters, one class of genotoxic impurities (GTIs), have gained significant attention in recent years due to their potential to cause genetic mutations and cancer. In the current study, we employed the dummy template molecular imprinting technology with a dummy template molecule replacing the target molecule to establish a pretreatment method for samples containing p-toluene sulfonate esters. Through computer simulation and ultraviolet-visible spectroscopy analysis, the optimal functional monomer acrylamide and polymerization solvent chloroform were selected. Subsequently, a dummy template molecularly imprinted polymer (DMIP) was prepared by the precipitation polymerization method, and the polymer was characterized in morphology, particle size, and composition. The results of the adsorption and enrichment study demonstrated that the DMIP has high adsorption capability (Q = 7.88 mg/g) and favorable imprinting effects (IF = 1.37); Further, it could simultaneously adsorb three p-toluene sulfonate esters. The optimal adsorption conditions were obtained by conditional optimization of solid-phase extraction (SPE). A pH 7 solution was selected as the loading condition, the methanol/1 % phosphoric acid solution (20:80, v/v) was selected as the washing solution, and acetonitrile containing 10 % acetic acid in 6 mL was selected as the elution solvent. Finally, we determined methyl p-toluene sulfonate alkyl esters, ethyl p-toluene sulfonate alkyl esters, and isopropyl p-toluene sulfonate alkyl esters in tosufloxacin toluene sulfonate and capecitabine at the 10 ppm level (relative to 1 mg/mL active pharmaceutical ingredient (API) samples) by using DMIP-based SPE coupled with HPLC. This approach facilitated the selective enrichment of p-toluene sulfonate esters GTIs from complex API samples.

Molecular-Imprinting-Based Surface-Enhanced Raman Scattering Sensors

Molecularly imprinted polymers (MIPs) receive extensive interest, owing to their structure predictability, recognition specificity, and application universality as well as robustness, simplicity, and inexpensiveness. Surface-enhanced Raman scattering (SERS) is regarded as an ideal optical detection candidate for its unique features of fingerprint recognition, nondestructive property, high sensitivity, and rapidity. Accordingly, MIP based SERS (MIP-SERS) sensors have attracted significant research interest for versatile applications especially in the field of chemo- and bioanalysis, showing excellent identification and detection performances. Herein, we comprehensively review the recent advances in MIP-SERS sensors construction and applications, including sensing principles and signal enhancement mechanisms, focusing on novel construction strategies and representative applications. First, the basic structure of the MIP-SERS sensors is briefly outlined. Second, novel imprinting strategies are highlighted, mainly including multifunctional monomer imprinting, dummy template imprinting, living/controlled radical polymerization, and stimuli-responsive imprinting. Third, typical application of MIP-SERS sensors in chemo/bioanalysis is summarized from both small and macromolecular aspects. Lastly, the challenges and perspectives of the MIP-SERS sensors are proposed, orienting sensitivity improvement and application expanding.

Dummy molecularly imprinted solid phase extraction of climbazole from environmental water samples

Dummy molecularly imprinted polymer (DMIP) for climbazole (CBZ) was synthesized for the first time employing miconazole (MNZ) as the dummy template together with methacrylic acid (MAA) monomer, ethylene glycol dimethacrylate (EGDMA) cross-linker and acetonitrile (ACN) porogen. The selectivity and capacity of the prepared MNZ-DMIP was estimated for CBZ by high-performance liquid chromatography (HPLC) and equilibrium binding experiments. Imprinting factor (IF) with a value of 7.0 was achieved, much higher than the CBZ templated MIP (IF = 3.5). Heterogeneous binding sites were found in the MNZ-DMIP, the corresponding saturation capacity and dissociation constant for the high and low affinity binding sites were 6.761 μmol g^-1 and 0.3027 mmol L^-1, 43.60 μmol g^-1 and 4.055 mmol L^-1, respectively. High efficient method based on dummy molecularly imprinted solid phase extraction (DMISPE) coupled with HPLC was established for the selective enrichment of CBZ in river and tap water using MNZ-DMIP as sorbent. DMISPE conditions including sample loading pH/volume, selective washing and elution solvents were carefully optimized. The developed method showed good recoveries (82.3-96.2%) and repeatability (RSDs 0.6-4.9%, n = 5) for samples spiked at three different concentration levels (0.2, 1.0 and 5.0 μg L^-1). The detection limit was determined as 0.012 μg L^-1. The results demonstrated good potential of this method for sample pretreatment of CBZ in environmental water samples.

Surface Plasmon Resonance-Based Fiber Optic Sensors Utilizing Molecular Imprinting

Molecular imprinting is earning worldwide attention from researchers in the field of sensing and diagnostic applications, due to its properties of inevitable specific affinity for the template molecule. The fabrication of complementary template imprints allows this technique to achieve high selectivity for the analyte to be sensed. Sensors incorporating this technique along with surface plasmon or localized surface plasmon resonance (SPR/LSPR) provide highly sensitive real time detection with quick response times. Unfolding these techniques with optical fiber provide the additional advantages of miniaturized probes with ease of handling, online monitoring and remote sensing. In this review a summary of optical fiber sensors using the combined approaches of molecularly imprinted polymer (MIP) and the SPR/LSPR technique is discussed. An overview of the fundamentals of SPR/LSPR implementation on optical fiber is provided. The review also covers the molecular imprinting technology (MIT) with its elementary study, synthesis procedures and its applications for chemical and biological anlayte detection with different sensing methods. In conclusion, we explore the advantages, challenges and the future perspectives of developing highly sensitive and selective methods for the detection of analytes utilizing MIT with the SPR/LSPR phenomenon on optical fiber platforms.

Molecular imprinting: perspectives and applications

This critical review presents a survey of recent developments in technologies and strategies for the preparation of MIPs, followed by the application of MIPs in sample pretreatment, chromatographic separation and chemical sensing.

Selective photodegradation of 2-mercaptobenzothiazole by a novel imprinted CoFe2O4/MWCNTs photocatalyst

Photocatalytic activity of a novel imprinted CoFe₂O₄/MWCNTs photocatalyst is enhanced by introducing PPy into the surface-imprinted layer, and the novel imprinted CoFe₂O₄/MWCNTs photocatalyst possesses better selection for the degradation of MBT.

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.

Preparation of a molecularly imprinted polymer using TMB as a dummy template and its application as SPE sorbent for determination of six PBBs in and fish samples

A novel molecularly imprinted polymer (MIP) based on a silica-gel surface for the separation and concentration of polybrominated biphenyls (PBBs) was prepared using 3,3',5,5'-tetramethylbenzidine (TMB) as a dummy template by a surface molecular imprinting technique in combination with a sol-gel process. The results obtained from a series of adsorption experiments proved that the prepared sorbent had a good adsorption capacity and a fast mass transfer rate to TMB. Meanwhile, a method was developed for the determination of six PBBs using TMB-MIP as a solid-phase extraction (SPE) enrichment sorbent coupled to GC-ECD. Under the optimum experimental conditions, the linear range of the calibration curve was 0.01-5.0 μg L-1 (r2 > 0.99), and LODs for each analyte were between 2.0 ng L-1 and 8.0 ng L-1. Relative standard deviations (RSD) for nine replicate detections of 1.0 μg L-1 of each analyte ranged from 4.30% to 7.89%. The proposed method was applied to the determination of six PBBs in spiked water and fish samples with recoveries ranging from 61.48% to 114.06%.