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A carbon dots-embedded epitope imprinted polymer (C-MIP) was fabricated for targeted fluorescence imaging of cervical cancer by specifically recognizing the epidermal growth factor receptor (EGFR). The core-shell C-MIP was prepared by a reverse microemulsion polymerization method. This method used silica nanoparticles embedded with carbon dots as carriers, acrylamide as the main functional monomer, and N-terminal nonapeptides of EGFR modified by palmitic acid as templates. A series of characterizations (transmission electron microscope, dynamic light scattering, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, zeta potential, and energy dispersive X-ray spectroscopy) prove the successful synthesis of C-MIP. The fluorescence of C-MIP is quenched by the epitopes of EGFR due to the specific recognition of epitopes of EGFR through their imprinted cavities (analytical excitation/emission wavelengths, 540 nm/610 nm). The linear range of fluorescence quenching is 2.0 to 15.0 μg mL−1 and the determination limit is 0.73 μg mL−1. The targeted imaging capabilities of C-MIP are demonstrated through in vitro and in vivo experiments. The laser confocal imaging results indicate that HeLa cells (over-expression EGFR) incubated with C-MIP show stronger fluorescence than that of MCF-7 cells (low-expression EGFR), revealing that C-MIP can target tumor cells overexpressing EGFR. The results of imaging experiments in tumor-bearing mice exhibit that C-MIP has a better imaging effect than C-NIP, which further proves the targeted imaging ability of C-MIP in vivo. [ABSTRACT FROM AUTHOR]

Epitope imprinted polymer nanoparticles (EI-NPs) were prepared by one-pot polymerization of N-isopropylacrylamide in the presence of CdTe quantum dots and an epitope (consisting of amino acids 598 to 609) of human serum albumin (HSA). The resulting EI-NPs exhibit specific recognition ability and enable direct fluorescence quantification of HSA based on a fluorescence turn-on mode. The polymer was characterized by FT-IR, X-ray photoelectron spectroscopy, transmission electron microscopy and dynamic light scattering. The linear calibration graph was obtained in the range of 0.25-5 μmol · mL with the detection limit of 44.3 nmol · mL. The EI-NPs were successfully applied to the direct fluorometric quantification of HSA in samples of human serum. Overall, this approach provides a promising tool to design functional fluorescent materials with protein recognition capability and specific applications in proteomics. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Protein-imprinted polymers with hollow cores that have a super-high imprinting factor were prepared by etching the core of the surface-imprinted polymers that used silica particles as the support. Lysozyme as template was modified onto the surface of silica particles by a covalent method, and after polymerization and the removal of template molecules, channels through the polymer layer were formed, which allowed a single-protein molecule to come into the hollow core and attach to the binding sites inside the polymer layer. The adsorption experiments demonstrated that the hollow imprinted polymers had an extremely high binding capacity and selectivity, and thus a super-high imprinting factor was obtained. The as-prepared imprinted polymers were used to separate the template lysozyme from egg white successfully, indicating its high selectivity and potential application in the field of separation of protein from real samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • D-EMIPs can target HER2 and IMPDH simultaneously by epitope imprinting method. • D-EMIPs target HER2+ cells and inhibit nucleotide metabolism to inhibit tumor. • Targeted metabolism therapy reduces biotoxicity, offering precise tumor inhibition. • Epitope imprinting combined with antimetabolism: a novel cancer treatment approach. Nucleotide metabolism therapeutics, aimed at disrupting nucleic acid production, have proven to be an effective strategy against cancers. Traditionally, these therapies rely on classical antimetabolites such as fluorouracil and mercaptopurine; however, they suffer from the drawback of high biotoxicity. In this study, we introduced a novel approach using dual-template epitope molecularly imprinted polymers (D-EMIPs), designed with the nucleotide metabolism therapy strategy in mind for precise targeting and cancer treatment. The imprinting process comprised two key template peptides: the active center peptide of inosine 5′-monophosphate dehydrogenase (IMPDH) and epitope of the human epidermal growth factor receptor-2 (HER2). The D-EMIPs could selectively bind to IMPDH and occupy its catalytic active sites, thereby suppressing enzymatic reactions and inhibiting DNA and RNA synthesis, ultimately impeding tumor growth. Furthermore, by specifically targeting HER2, an overexpressed protein in certain cancer types, D-EMIPs enhanced the therapeutic efficacy for HER2-positive (HER2+) cancers. In vitro experiments suggested that D-EMIPs could selectively target HER2+ tumor cells, leading to a substantial 41% reduction in cell proliferation. In vivo experiments further confirmed the tumor-specific targeting capability of D-EMIPs, resulting in smaller tumor volumes compared to the control group treated with phosphate-buffered saline (PBS). These findings emphasize the promise of combining nucleotide metabolism therapeutics with the dual-template imprinted technique as a comprehensive strategy to establish an integrated platform for cancer diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Abstract A quartz crystal microbalance (QCM) sensor for detecting cytochrome c based on an oriented surface epitope imprinted polymer was fabricated in this paper. By using the palmitic acid-modified epitope of cytochrome c as the template and the 3-aminopropyltriethoxysilane as the monomer, we prepared a new oriented surface epitope imprinted polymer by the reverse microemulsion polymerization. The prepared oriented imprinted polymer had better imprinting effect than the non-oriented imprinted polymer. And compared to previous studies, this polymerization method is simple and could be carried out at room temperature in the presence of oxygen, under regular atmospheric conditions. Then, by combining the advantages of molecularly imprinted polymers and QCM sensors, we used the prepared polymer to establish a QCM sensor. The described sensor showed good sensitivity and selectivity towards cytochrome c. The linear range was from 0.005 μg mL−1 to 0.050 μg mL−1 and the detection limit was 3.6 ng mL−1 which is lower than most of previous works. Besides, it could be used for real sample analysis and had satisfactory reproducibility and accuracy. This work proposed a new way of fabricating oriented surface epitope imprinted polymers-based QCM sensors for selectively detecting proteins at very low concentrations. Graphical abstract fx1 Highlights • A new quartz crystal microbalance sensor was successfully modified by an oriented surface epitope imprinted polymer. • Compared to previous studies, the preparation of the polymer was simpler, easier and without harsh environment. • This oriented imprinted polymer had better imprinting effect than the non-oriented one. • This protocol introduced the hydrolysis of tetraethoxysilane into oriented epitope imprinting for the first time. • This sensor had lower detection limit than most of the previous studies and is promising for real sample analysis. [ABSTRACT FROM AUTHOR]

Quantitative determination of biomacromolecules has great significance. Quartz crystal microbalance sensors are favored by their sensibility while their selectivity was limited. Molecularly imprinted polymer has great selectivity performance. By combining the advantages of quartz crystal microbalance and molecularly imprinted polymer, this work established an epitope molecularly imprinted polymer based quartz crystal microbalance sensor. Using the epitope of human serum albumin as the template, the epitope molecularly imprinted polymer (EMIP) was successfully synthesized. Then a simple coating method was applied to fabricate the epitope molecularly imprinted polymer based quartz crystal microbalance sensor (EMIP-QCM). The EMIP-QCM sensor had good sensibility and selectivity to the target human serum albumin. The linear range was from 0.050 μg mL −1 to 0.500 μg mL −1 and the detection limit was calculated to be 0.026 μg mL −1 . In addition, it could be used in real sample analysis and had good accuracy and reproducibility. This method proposed a general and simple way of establishing quartz crystal microbalance sensors for sensitive determination of biomacromolecules. [ABSTRACT FROM AUTHOR]

A new type of thermo-sensitive receptor carbon dots/SiO 2 /molecularly imprinted polymer (CDs/SiO 2 /MIP) was prepared by surface imprinting procedure and the epitope approach. The synthetic CDs/SiO 2 /MIP was able to selectively capture target protein with fluorescence quenching via the special interaction between them and the recognition cavities. The receptor exhibited the linear fluorescence quenching to cytochrome c (cyt c) in the range of 0.1–40 μM, and the detection limit was 89 nM. The precision for five replicate detection of cyt c at 20 μM was 3.11%. Moreover, the receptor owned the temperature-sensitive element that allowed for swelling and shrinking in response to temperature changes to realize recognition of the target cytochrome c. The proposed strategy revealed the feasibility of fabrication of a thermo-sensitive imprinted polymer based on CDs and surface imprinting procedure and the epitope approach. [ABSTRACT FROM AUTHOR]

Abstract: A novel epitope molecularly imprinted polymer (EMIP) for specific recognition and direct fluorescent quantification of the target protein bovine serum albumin (BSA) was demonstrated where polymerization was performed on the surface of silica nanospheres embedded CdTe quantum dots (QDs). The synthetic peptide derived from the surface-exposed C-terminus of bovine serum albumin (BSA, residues 599-607) was selected as the template molecule. The resulting EMIP film was able to selectively capture the template peptide and the corresponding target protein BSA via the recognition cavities. Based on the fluorescence quenching, the EMIP-coated QDs (molecular imprinted polymer coating CdTe QDs using epitope as the template) nanospheres were successfully applied to the direct fluorescence quantification of BSA. Compared with BMIP-coated QDs (molecular imprinted polymer coating CdTe QDs using BSA as the template), the imprinting factor and adsorption capacity of EMIP-coated QDs were greatly increased. The prepared EMIP-coated QDs can also discriminate even one mismatched sequences from the original sequences of the epitope of the BSA. The practical analytical performance of the EMIP-coated QDs was examined by evaluating the detection of BSA in the bovine calf serum sample with satisfactory results. In addition, the resulting EMIP-coated QDs nanospheres were also successfully applied to separating BSA from the bovine blood sample. [Copyright &y& Elsevier]

Abstract: A new type of molecularly imprinted polymer (MIP)-based fluorescent artificial receptor was developed by anchoring MIP on the surface of denatured bovine serum albumin (dBSA) modified CdTe quantum dots (QDs) using the surface molecular imprinting process. The approach combined the merits of molecular imprinting technology and the fluorescent property of the CdTe QDs. The dBSA was used not only to modify the surface defects of the CdTe QDs, but also as assistant monomer to create effective recognition sites. Three different proteins, namely lysozyme (Lyz), cytochrome c (Cyt) and methylated bovine serum albumin (mBSA), were tested as the template molecules and then the receptors were synthesized by sol–gel reaction (imprinting process). The results of fluorescence and binding experiments demonstrated the recognition performance of the receptors toward the corresponding template. Under optimum conditions, the linear range for Lyz was from 1.4×10−8 to 8.5×10−6 M, and the detection limit was 6.8nM. Moreover, the new artificial receptors were applied to separate and detect Lyz in real samples. This fluorescent artificial receptor may serve as a starting point in the design of highly effective synthetic fluorescent receptor for recognition of target protein. [Copyright &y& Elsevier]

Abstract: Molecular imprinting as a promising and facile separation technique has received much attention because of their high selectivity for target molecules. In this study, the superparamagnetic lysozyme surface-imprinted polymer was prepared by a novel fabricating protocol, the grafting of the imprinted polymer on magnetic particles in aqueous media was done by atom transfer radical polymerization (ATRP), and the properties of the imprinted polymer were characterized in detail. Its high selective adsorption and recognition to lysozyme demonstrated the separation ability of the magnetic imprinted material to template molecule, and it has been used for quick and direct separation of lysozyme from the mixture of standard proteins and real egg white samples under an external magnetic field. Furthermore, the elution of lysozyme from the imprinted material was achieved by PEG/sulphate aqueous two-phase system, which caused lysozyme not only desorption from the imprinted materials but also redistribution in the top and bottom phase of aqueous two-phase system. The aqueous two-phase system exhibited some of the extraction and enrichment effect to desorbed lysozyme. Our results showed that ATRP is a promising method for the protein molecularly imprinted polymer preparation. [Copyright &y& Elsevier]

Abstract: A novel protein imprinted polymer was prepared using acryloyl-β-cyclodextrin (β-CD) and acrylamide as monomers on the surface of silica gel. The bovine hemoglobin was used as template and β-CD was allowed to self-assemble with the template protein through hydrogen bonding and hydrophobic interaction. Polymerization was carried out in the presence of acrylamide as an assistant monomer, which resulted in a novel protein imprinted polymer. After removing the template, imprinted cavities with the shape and spatial distribution of functional groups were formed. Bovine serum albumin (BSA) cytochrome c (Cyt) and lysozyme (Lyz) were employed as non-template proteins to test the imprinting effect and the specific binding of bovine hemoglobin to the polymer. The results of the adsorption experiments indicated that such protein imprinted polymer, which was synthesized with β-CD and acrylamide as monomers, could selectively recognize the template protein. [Copyright &y& Elsevier]

Abstract: A novel protein imprinted polymer for selective recognition of lysozyme was obtained. Acryloyl-β-cyclodextrin, which offered hydrophilic exterior and hydrophobic cavity that were allowed to self-assemble with the template protein through hydrogen interaction and hydrophobic interaction, was synthesized and used as the functional monomer. Polymerization was carried out in the presence of acrylamide as an assistant monomer, which resulted in a new type of protein imprinted polymer. Langmuir adsorption model was employed to describe the isotherms, and maximum adsorption capacity was evaluated. The performance of such imprinted polymer was further demonstrated by high-performance liquid chromatography, and the results showed that the column packed with the lysozyme imprinted silica beads could effectively separate lysozyme from the mixture of lysozyme–cytochrome c, lysozyme–bovine serum albumin, lysozyme–avidin or lysozyme–methylated bovine serum albumin, which showed its high selectivity. [Copyright &y& Elsevier]

Abstract: A new and facile fabricating method for lysozyme molecularly imprinted polymer beads (lysozyme-MIP beads) in aqueous media was presented. Mesoporous chloromethylated polystyrene beads (MCP beads) containing dithiocarbamate iniferter (initiator transfer agent terminator) were used as supports for the grafting of lysozyme imprinted copolymers with acrylamide and N,N′-methylenebisacrylamide through surface initiated living-radical polymerization (SIP). After the polymerization, a layer of lysozyme-MIP was formed on the MCP beads. The SIP allowed an efficient control of the grafting process and suppressed solution propagation. Therefore, the obtained lysozyme-MIP beads had a large quantity of well-distributed pores on the surface without any visible gel formation in solution and were more advantageous comparing with traditional MIPs which were prepared by traditionally initiated radical polymerization. The obtained composites were characterized by Fourier transform infrared spectroscopy, elemental analysis, nitrogen sorption analysis and scanning electron microscopy. Chromatographic behaviors of the column packed with lysozyme-MIP beads exhibited ability in separating lysozyme from competitive protein (bovine hemoglobin, bovine serum albumin, ovalbumin or cytochrome c) in aqueous mobile phase. [Copyright &y& Elsevier]

Abstract: A novel molecularly imprinted polymer (MIP) selective for tryptophan (Trp) was described where polymerization was performed in aqueous media. Three kinds of molecularly imprinted polymers were prepared with surface molecular imprinting technique on functionalized silica gel (F-silica gel). MIPs prepared using bonded β-cyclodextrin (β-CD) and acrylamide (AA), either separately or in combination have shown various recognition properties. The results of adsorption experiments indicated that the selectivity of MIP, which was synthesized with bonded β-CD and AA [MIP(1)], was superior to those obtained with AA [MIP(2)] or bonded β-CD [MIP(3)]. In addition, the high-performance liquid chromatography (HPLC) column packed with MIP(1) could not only separate Trp from other aromatic amino acids, but also separate the template from its enantiomer in aqueous mobile phase. This study developed a new method for chiral amino acid separation and purification. [Copyright &y& Elsevier]

Molecularly imprinted polymer nanozyme (MIL-101(Co,Fe)@MIP) with bimetallic active sites and high-efficiency peroxidase-like (POD-like) activity were synthesized for the ratiometric fluorescence and colorimetric dual-mode detection of vanillin with high selectivity and sensitivity. Compared with the monometallic nanozyme, the POD-like activity of bimetallic nanozyme was greatly enhanced by changing the electronic structure and surface structure. Ratiometric fluorescence and colorimetric dual-mode detection of vanillin in aqueous solution was realized by vanillin entering specific imprinted cavities and blocking the molecular channels on the surface of MIL-101(Co,Fe)@MIP and the dual-mode visual detection was also realized. The limits of detection were as low as 104 nM and 198 nM, respectively. The method proposed in this paper was applied to the real samples of ice cream and candy. And the recoveries were between 93.3% and 105.5%, which also reached a satisfactory degree. The further detection of dexamethasone and prednisone, two drugs belonging to glucocorticoid, proved that the nanozyme analysis method based on MIL-101(Co,Fe)@MIP could be developed into a sensing platform. • The bimetallic active sites molecularly imprinted polymer was innovatively synthesized. • MIL-101(Co,Fe)@MIP nanozyme has high-efficiency peroxidase-like activity. • The method of ratiometric fluorescence and colorimetric dual-mode sensing platform was built. • The visual detection was realized. [ABSTRACT FROM AUTHOR]

In this work, we innovatively synthesized homochiral fluorescence nano molecularly imprinted polymers (D-MIP) with dual affinity (metal ion affinity and homochiral affinity) for the specific separation and detection of L-penicillamine (L-PA), which is a core-shell structure with a SiO 2 -covered CDs core and an imprinted layer with L-PA cavities. A switch for fluorescence response was built by chelating grafted Cu2+, what's more, the imprinted L-PA was pre immobilized by Cu2+ to form the directional imprinting with predetermined spatial structure. More importantly, the homochiral affinity of D-galactose in homochiral molecularly imprinted polymers (D-MIP) greatly enhanced the selective adsorption of L-PA, and D-MIP showed a high selectivity factor (α) of 3.45, which is 1.9 times that of the non-homochiral molecularly imprinted polymers (MIP). Meanwhile, D-MIP exhibited a high enantiomeric excess (ee) value of 56% for separation of racemic PA. Additionally, a high sensitive and selective method was established for the detection of L-PA. [Display omitted] • The homochiral fluorescence nano molecularly imprinted polymers (D-MIP) was innovatively synthesized. • The dual role of copper ion: the switch of fluorescence responsive and the inducer of directional imprinting. • The presence of homochiral D-galactose greatly improved the enantiomer separation efficiency of D-MIP. • An approach was built for the detection of L-PA. [ABSTRACT FROM AUTHOR]

Early and accurate detection of breast cancer plays an important role in improving the survival rates of patients. In this work, we designed and synthesized the Gal-NAc-imprinted nanoparticles (GIPs) via boronate-affinity glycan-oriented surface imprinting strategy. Molecularly imprinted polymers (MIPs) were hybridized with fluorescent silicon nanoparticles (SiNPs) to target Tn antigens. However, the single fluorescent imaging mode is not conducive to obtaining accurate diagnosis, due to its poor tissue penetration. To resolve this obstacle, doping gadolinium (Gd) into SiNPs was adopted to emerge an extra significant magnetic resonance (MR) signal, achieving highly sensitive fluorescence imaging and magnetic resonance imaging (MRI) with high spatial resolution. GIPs had uniform particle size around 31.8 nm, and exhibited satisfactory fluorescence stability. The maximum adsorption capacity of GIPs was 1.15 μM/g with a high imprinting factor (IF) of 7.5. Confocal laser scanning microscope imaging revealed that the GIPs had excellent specific recognition ability with a low cytotoxicity. GIPs also showed an outstanding MR performance on cancer cells. Therefore, the synthesized nanoparticles had desirable performance in dual-model imaging to specifically target recognition cancer cells. It may have a tremendous potential in real biological samples. Image 1 • A new glycan-oriented imprinted polymer was synthesized by boronate-affinity surface imprinting method. • This polymer had uniform particle size, satisfactory fluorescence stability and low cytotoxicity. • This polymer can specifically recognize Tn antigens. • Hybridized with Gd-doped silicon nanoparticles, this polymer had the capabilities of fluorescence imaging and MR imaging. [ABSTRACT FROM AUTHOR]