A molecularly imprinted photopolymer based on mesh TpPa-2 embedded with perovskite CsPbBr3 quantum dots for the sensitive solid fluorescence sensing of patulin in apple products.

Here, a novel molecularly imprinted photopolymer was prepared using CsPbBr3 quantum dots as the fluorescence source, TpPa-2 as substrate for selective solid fluorescence detection of patulin (PAT). TpPa-2 can promote efficient recognition of PAT due to its unique structure and significantly improve the fluorescence stability and sensitivity. The test results showed that the photopolymer exhibited large adsorption capacity (131.75 mg/g), fast adsorption ability (12 mins), superior reusability and high selectivity. The sensor proposed had good linearity for PAT in the range of 0.2-20 ng/mL and was applied to the analysis of PAT in apple juice and apple jam with a limit of detection as low as 0.027 ng/mL. Therefore it maybe a promising method for solid fluorescence detection of trace PAT in food analysis.

Molecularly imprinted electrochemical sensor based on 3D-flower-like MoS2 decorated with silver nanoparticles for highly selective detection of butylated hydroxyanisole.

This study introduces an innovative procedure for the development of a molecularly imprinted electrochemical sensor for ultra-sensitive and specific recognition of butylated hydroxyanisole (BHA). First, a uniquely flower-like molybdenum disulfide/Ag nanoparticle-chitosan (MoS2/Ag NPs-CS) composite was prepared and used as a matrix to modify the electrode surface. Then, a layer of BHA-molecularly imprinted polymer was grown on the surface of the modified electrode by electropolymerization, with BHA as template molecule, which improved the specific recognition of the modified electrode to BHA. The MoS2/Ag NPs-CS material could not only increase the specific surface area of the electrode, accelerate the electron transport rate and mass transfer, but also promote the recognition of the polymer, so as to increase the current response and improve the performance of the electrochemical sensor. The prepared electrochemical sensor showed a wide linear range for BHA in the range of 1 × 10-9-1 × 10-4 mol/L with a detection limit of 7.9 × 10-9 mol/L. The recovery of BHA in several foods was from 95% to 103%. The sensor had good reproducibility, stability and excellent selectivity, and was successfully used for the detection of BHA in foods, providing a reliable detection method for sensitive, rapid and selective detection of BHA in complex food samples.

Preparation of mesh covalent organic framework Tppa-2-based adsorption enhanced magnetic molecularly imprinted composite for selective extraction of tetracycline residues from animal-derived foods.

In this study, for the first time, core-shell tetracycline hydrochloride-molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization using a magnetic covalent organic framework (Fe3O4@Tppa-2) synthesized by room-temperature ultrasonic method as a substrate. Introducing Fe3O4@Tppa-2 into the molecular imprinting system can be used for efficient shortens the time for the adsorption equilibrium of MIPs due to its unique pore structure. The maximum adsorption capacity of MIPs was 87.50 mg/g, and the adsorption equilibrium reached in 14 min. The MIPs were used as magnetic solid-phase extraction sorbents in combination with high performance liquid chromatography for the determination of tetracycline in pork, chicken and chicken liver, and the detection limit reached 0.01 ng/mL. In addition, the adsorption advantages of MIPs suggest that it is a promising adsorbent for the recovery of antibiotics and has potential applications in the detection and enrichment of TC in food.

A molecularly imprinted polymer based on MOF and deep eutectic solvent for selective recognition and adsorption of bovine hemoglobin.

In this study, a novel kind of imprinted polymers based on metal-organic frameworks (MOF@DES-MIPs) was prepared, using bovine hemoglobin (BHb) as template molecules and deep eutectic solvents (DES) as functional monomers for selective recognition and adsorption of BHb. MOF were used as the substrates to improve the accessibility of imprinted sites and DES as the functional monomers to produce different forces for BHb to help the formation of imprinted sites. Imprinted polymer films were taken to provide analyte selectivity. The MOF@DES-MIPs prepared were characterized and evaluated by scanning electron microscope, X-ray diffraction, and Fourier transform infrared spectrometer. We also investigated the influences of BHb concentration and adsorption time on the performance of MOF@DES-MIPs. The maximal adsorption capacity of MOF@DES-MIPs to BHb reached 151.28 mg g-1, and the MOF@DES-MIPs showed good selectivity and fast adsorption equilibrium, which might offer a novel method for the preparation and research of molecularly imprinted polymers of biomacromolecules. In addition, MOF@DES-MIPs were successfully applied in the selective recognition of BHb from a real bovine blood sample. Graphical abstract.

Determination of chloropropanol with an imprinted electrochemical sensor based on multi-walled carbon nanotubes/metal-organic framework composites.

In this paper, a composite composed of carboxylated multi-wall carbon nanotubes (cMWCNT) incorporated in a metal-organic framework (MOF-199) has been synthesized using 1,3,5-benzoic acid as a ligand through a simple solvothermal method. The synthesized cMWCNT/MOF-199 composite was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffractometry (XRD). The cMWCNT/MOF-199 hybrids were modified on the surface of glassy carbon electrodes (GCE) to prepare a molecularly imprinted electrochemical sensor (MIECS) for specific recognition of 3-chloro-1,2-propanediol (3-MCPD). The electrodes were characterized by differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Under optimal conditions, the electrochemical sensor exhibited an excellent sensitivity and high selectivity with a good linear response range from 1.0 × 10-9 to 1.0 × 10-5 mol L-1 and an estimated detection limit of 4.3 × 10-10 mol L-1. Furthermore, this method has been successfully applied to the detection of 3-MCPD in soy sauce, and the recovery ranged from 96% to 108%, with RSD lower than 5.5% (n = 3), showing great potential for the selective analysis of 3-MCPD in foodstuffs.

Drug-loaded dual targeting graphene oxide-based molecularly imprinted composite and recognition of carcino-embryonic antigen.

Despite extensive research on functional graphene oxide for anticancer drug delivery, the sensitivity of traditional protein targeting ligands to the environment limits the practical applications of targeted drug delivery. A unique molecularly imprinted magnetic graphene oxide was used as a novel drug delivery system for the treatment of tumors. Molecularly imprinted polymers (MIPs) synthesized by molecular imprinting technology have the advantages of good stability against chemical and enzymatic attacks, high specificity for a target template, and resistance to harsh environments. In our work, the MIP was used for specificity to tumor cells with carcino-embryonic (CEA) tumor markers as the template, and dopamine as the functional monomer was grafted on boronic acid-functionalized magnetic graphene oxide. The structure of the nanoparticles was optimized and characterized in detail by vibrating sample magnetometry, X-ray diffraction analysis, UV-vis spectroscopy, and flow cytometry. The prepared polymer has magnetic properties, specific recognition to CEA, biocompatibility and pH sensitivity for drug delivery. Cell culture research was carried out on the tumor cells and normal cells. The composites exhibited dual targeting properties that not only magnetically target but also specifically increase the drug cytotoxicity to the tumor cells by selectively binding to CEA. On the basis of these results, this study developed a novel approach for targeting tumor cells for drug delivery without needing to modify the protein ligand.