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Transferrin-functionalized silicon nanoparticles (Trf-SiNPs) with two-photon-excited fluorescence were fabricated and utilized for targeted fluorescence imaging in tumor cells. [Display omitted] • A facile and feasible fluorescence probe of transferrin-functionalized SiNPs were fabricated. • Trf-SiNPs featured the excellent optical properties, especially the up-conversion fluorescence. • Trf-SiNPs exhibited the good targeted fluorescence imaging capability in tumor cells. • Trf-SiNPs demonstrated the satisfactory two-photon imaging ability in tumor cells. Transferrin-functionalized silicon nanoparticles (Trf-SiNPs) were fabricated and utilized for targeted fluorescence imaging in tumor cells. Silicon nanoparticles (SiNPs) was firstly synthesized by microwave irradiation method, and then coupled with transferrin in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The structural informations of Trf-SiNPs were measured by transmission electron microscope and Fourier transform infrared spectrometer. The optical properties of Trf-SiNPs were characterized by ultraviolet absorption spectrum, fluorescence emission spectrum, fluorescence quantum yield, fluorescence lifetime, photo-stability, and so on. MTT assay evidenced the low toxicity of Trf-SiNPs. Finally, Trf-SiNPs were successfully applied in HeLa cells and HepG2 cells for targeted fluorescence imaging under single-photon excitation and two-photon excitation. [ABSTRACT FROM AUTHOR]

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]

The determination approaches of Fe (Ⅲ) in biological samples were developed by a novel water-soluble silicon nanoparticles (SiNPs). The SiNPs were synthesized by a facile microwave-assisted method, and simultaneously featured strong blue fluorescence (photoluminescence quantum yield: 25.2%), long lifetime (~13.29 ns) and good photo-stability. The fluorescence intensities of SiNPs were gradually quenched with Fe (Ⅲ) concentration increasing from 2.0 to 50 μmol/L. The detection limit of the established method was 0.56 μmol/L and the precision for eleven replicate detections of 20 μmol/L Fe (Ⅲ) was 3.2% (relative standard deviation, RSD). The spiked recoveries were 99.0%–104.5%. Results of the lifetime decay and cyclic voltammetry (CV) evidenced that the electron transfer was responsible for the fluorescence quenching mechanism of SiNPs and Fe (Ⅲ). Moreover, the SiNPs were successfully applied in the determination of Fe(Ⅲ) in different environmental waters and human serum. Finally, the resulting SiNPs exhibited the green fluorescence in HeLa cells as the optical probe. [Display omitted] • A facile and feasible determination method of Fe (Ⅲ) ion was established based on the novel fluorescence SiNPs probe. • SiNPs featured bright blue fluorescence ,long lifetime and superbly strong stability. • Fluorescence quenching mechanism between SiNPs and Fe (Ⅲ) ion was evidenced by lifetime decay and cyclic voltammetry. • SiNPs could be applied as the fluorescence probe for determination of Fe (Ⅲ) ion in real samples. [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]

Currently, the nanocomposites based on silicon nanoparticles (SiNPs) are usually limited to a single therapeutic modality, and the design of the SiNPs nanohybrids with multi-modal synergistic therapeutic functions is still worth being explored to achieve more effective treatment. Herein, we used mesoporous silica nanoparticle (MSN) as a nanoplatform, SiNPs and the photosensitizer 5,10,15,20-tetrakis (1-methyl 4-pyridinio) porphyrin tetra (p-toluenesulfonate) (TMPyP) were first embedded in the MSN and was further modified with folic acid (FA) to obtain the mesoporous silica nanocomposite (MSN@SiNPs@TMPyP-FA) for targeted two-photon-excited fluorescence imaging-guided photodynamic therapy (PDT) and chemotherapy. The embedded TMPyP could generate singlet oxygen to perform PDT under light irradiation, meanwhile the anticancer drugs doxorubicin (DOX) could be loaded for chemotherapy. Moreover, due to the two-photon excited fluorescence of SiNPs, the nanocomposite successfully achieved targeted two-photon fluorescence cellular imaging at the near-infrared (NIR) laser excitation, which could effectively avoid the interference of biological auto-fluorescence. And in vitro cytotoxicity assays revealed that the synergistic therapy combining PDT and chemotherapy exhibited high therapeutic efficacy for cancer cells. Image 1 • A novelty mesoporous silica nanoplatform including silicon nanoparticles, photosensitizer and folic acid was fabricated. • Due to the silicon nanoparticles, the nanocomposite achieved precise targeted two-photon excited fluorescence imaging. • The multifunctional nanocomposites achieved more efficient chemotherapeutic/photodynamic synergistic therapy in vitro. [ABSTRACT FROM AUTHOR]

Macrophages have emerged as promising cellular vehicles for the delivery of therapeutic agents to tumor sites. However, the cytotoxicity of therapeutic agents toward the cellular carriers and the effective release of therapeutic agents at the tumor site remain the main challenges faced by macrophage-mediated drug delivery systems. Herein, a near-infrared (NIR)-triggered release of self-accelerating cascade nanoreactor (HCFG) delivered by macrophages (HCFG@R) was developed for synergistic tumor photothermal therapy (PTT)/starvation therapy (ST)/chemodynamic therapy (CDT). Attributed to the inherent tumor tropism of macrophages, HCFG@R could accumulate in tumor tissues and subsequently be disrupted by NIR laser, allowing the release of HCFG nanoparticles (NPs) from macrophage carriers. The released HCFG catalyzed the generation of O 2 from hydrogen peroxide (H 2 O 2 ), which in turn enhanced glucose oxidase (GOx)-mediated ST. Simultaneously, the H 2 O 2 and gluconic acid generated by ST could promote the production of hydroxyl radicals (·OH), thereby improving the therapeutic effect of CDT. The present study provides an innovative strategy for enhanced PTT/ST/CDT synergistic therapy through a macrophage-mediated delivery system., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Inc. All rights reserved.)

Nitrite (NO 2 - ) is widely present in the natural environment and human daily life. Excessive NO 2 - can cause harm to the environment and human health. Herein, silicon nanoparticles (SiNPs) with a fluorescence quantum yield of up to 70 % were synthesised using a one-pot hydrothermal method and combined with the common and inexpensive o-phenylenediamine (OPD) to achieve the detection of NO 2 - . Upon the addition of NO 2 - , the blue fluorescence of the SiNPs was quenched due to static quenching and Förster resonance energy transfer (FRET), while the yellow fluorescence of benzotriazole, the reaction product of OPD and NO 2 - , was enhanced, resulting in the fluorescence color change from blue to yellow. Based on these phenomena, a ratiometric fluorescence sensor integrated with smartphone imaging technology was developed. This sensor is notable for its portability, cost-effectiveness, and satisfactory detection limits (0.016 μM for ratiometric fluorescence and 1.64 μM for smartphone imaging). Importantly, it demonstrates high reliability and practicability in detecting NO 2 - in real water and food samples. This broadens the application of SiNPs in the sensing field and introduces new possibilities for NO 2 - detection in complex sample matrices., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Glycolysis provides tumors with abundant nutrients through glucose (Glu) metabolism. As a therapeutic target, precise targeting and effective inhibition of the glycolysis process remains a major challenge in anti-metabolic therapy. In this study, a novel dual-template molecularly imprinted polymer (D-MIP), capable of specifically recognizing glucose transporter member 1 (GLUT1) and hexokinase-2 (HK2) was prepared for anti-glycolytic tumor therapy. The imprinting factors of D-MIP for the recognition of the template molecules, the GLUT1 epitope and the HK2 epitope, were 2.1 and 2.5, respectively, enabling specific recognition of the entire target protein. Targeting GLUT1 with D-MIP could impede its Glu uptake, while simultaneously inhibiting the activity of cytoplasmic HK2, thereby reducing the metabolic rate of Glu. Cell experiments demonstrated that inhibition of HK2 resulted in downregulation of the downstream, products glucose-6-phosphate (6PG) and lactate (LA). In vitro and in vivo experimental results indicated that D-MIP exhibited significant targeting and inhibitory effects on GLUT1 and HK2, respectively, which suppressed tumor glycolysis and induced apoptosis in MCF-7 cells. Furthermore, mouse tumor models and hematoxylin-eosin (H&E) staining confirmed the excellent anti-tumor efficacy and favorable biocompatibility of D-MIP. This work represents the first design and development of a dual-template imprinted polymer targeting key transport channels and metabolic enzymes involved in glycolysis, advancing the research and application of anti-glycolytic tumor therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Given the threat to human health posed by the abuse of tetracycline (TC), the development of a portable, on-site methods for highly sensitive and rapid TC detection is crucial. In this work, we initially synthesized europium-doped silicon nanoparticles (Si Eu NPs) through a facile one-pot microwave-assisted method. Due to its blue-red dual fluorescence emission (465 nm/621 nm), which was respectively attributed to the silicon nanoparticles and Eu 3+ , Si Eu NPs were designed as a ratiometric fluorescent sensor for TC detection. For the dual-signal reverse response mechanism: TC quenched the blue emission from silicon nanoparticles through inner filter effect (IFE), and enhanced the red emission through "antenna effect" (AE) between TC and Eu 3+ , the nanoprobe was able to detect TC within a range of 0.2-10 μM with a limit of detection (LOD) of 10.7 nM. Notably, the equilibrium detection time was only 1 min, achieving rapid TC detection. Furthermore, TC was also measured in real samples (tap water, milk and honey) with recoveries ranging from 95.7 % to 117.0 %. More importantly, a portable smartphone-assisted on-site detection platform was developed, enabling real-time qualitative identification and semi-quantitative analysis of TC based on fluorescence color changes. This work not only provided a novel doped silicon nanoparticles strategy, but also constructed a ratiometric sensing platform with dual-signal reverse response for intuitive and real-time TC detection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Glycinamide ribonucleotide formyltransferase (GARFT) is an important enzyme in the folate metabolism pathway, and chemical drugs targeting GARFT have been used in tumor treatments over the past few decades. The development of novel antimetabolism drugs that target GARFT with improved performance and superior activity remains an attractive strategy. Herein, we proposed a targeted double-template molecularly imprinted polymer (MIP) for enhancing macrophage phagocytosis and synergistic antimetabolic therapy. The double-template MIP was prepared by imprinting the exposed peptide segment of the extracellular domain of CD47 and the active center of GARFT. Owing to the imprinted cavities on the surface of MIP, it can actively target cancer cells and mask the "do not eat me" signal upon binding to CD47 thereby blocking the CD47-SIRPα pathway and ultimately enhancing phagocytosis by macrophages. In addition, MIP can specifically bind to the active center of GARFT upon entry into the cells, thereby inhibiting its catalytic activity and ultimately interfering with the normal expression of DNA. A series of cell experiments demonstrated that MIP can effectively target CD47 overexpressed 4T1 cancer cells and inhibit the growth of 4T1 cells. The enhanced phagocytosis ability of macrophages-RAW264.7 cells was also clearly observed by confocal imaging experiments. In vivo experiments also showed that the MIP exhibited a satisfactory tumor inhibition effect. Therefore, this study provides a new idea for the application of molecular imprinting technology to antimetabolic therapy in conjunction with macrophage-mediated immunotherapy.

Protein phosphorylation is one of the most common and important post-translational modifications that regulates almost all life processes. In particular, protein phosphorylation regulates the development of major diseases such as tumors, neurodegenerative diseases, and diabetes. For example, excessive phosphorylation of Tau protein can cause neurofibrillary tangles, leading to Alzheimer's disease. Therefore, large-scale methods for identifying protein phosphorylation must be developed. Rapid developmentin efficient enrichment methods and biological mass spectrometry technologies have enabled the large-scale identification of low-abundance protein O -phosphorylation modifications in, allowing for a more thorough study of their biological functions. The N -phosphorylation modifications that occur on the side-chain amino groups of histidine, arginine, and lysine have recently received increased attention. For example, the biological function of histidine phosphorylation in prokaryotes has been well studied; this type of modification regulates signal transduction and sugar metabolism. Two mammalian pHis kinases (NME1 and NME2) and three pHis phosphatases (PHPT1, LHPP, and PGAM5) have been successfully identified using various biological methods. N -Phosphorylation is involved in multiple biological processes, and its functions cannot be ignored. However, N -phosphorylation is unstable under acidic and thermal conditions owing to the poor chemical stability of the P-N bond. Unfortunately, the current O -phosphorylation enrichment method, which relies on acidic conditions, is unsuitable for N -phosphorylation enrichment, resulting in a serious lag in the large-scale identification of protein N -phosphorylation. The lack of enrichment methods has also seriously hindered studies on the biological functions of N -phosphorylation. Therefore, the development of efficient enrichment methods that target protein N -phosphorylation is an urgent undertaking. Research on N -phosphorylation proteome enrichment methods is limited, hindering functional research. Thus, summarizing such methods is necessary to promote further functional research. This article introduces the structural characteristics and reported biological functions of protein N -phosphorylation, reviews the protein N -phosphorylation modification enrichment methods developed over the past two decades, and analyzes the advantages and disadvantages of each method. In this study, both antibody-based and nonantibody-dependent methods are described in detail. Owing to the stability of the molecular structure of histidine, the antibody method is currently limited to histidine phosphorylation enrichment research. Future studies will focus on the development of new enrichment ligands. Moreover, research on ligands will promote studies on other nonconventional phosphorylation targets, such as two acyl-phosphates (pAsp, pGlu) and S -phosphate (pCys). In summary, this review provides a detailed analysis of the history and development directions of N -phosphorylation enrichment methods.

Antimetabolites targeting thymidylate synthase (TS), such as 5-fluorouracil and capecitabine, have been widely used in tumor therapy in the past decades. Here, we present a strategy to construct mitochondria-targeted antimetabolic therapeutic nanomedicines based on fluorescent molecularly imprinted polymers (FMIP), and the nanomedicine was denoted as Mito-FMIP. Mito-FMIP, synthesized using fluorescent dye-doped silica as the carrier and amino acid sequence containing the active center of TS as the template peptide, could specifically recognize and bind to the active site of TS, thus inhibiting the catalytic activity of TS, and therefore hindering subsequent DNA biosynthesis, ultimately inhibiting tumor growth. The imprinting factor of FMIP reached 2.9, and the modification of CTPB endowed Mito-FMIP with the ability to target mitochondria. In vitro experiments demonstrated that Mito-FMIP was able to efficiently aggregate in mitochondria and inhibit CT26 cell proliferation by 59.9%. The results of flow cytometric analysis showed that the relative mean fluorescence intensity of Mito-FMIP accumulated in the mitochondria was 3.4-fold that of FMIP. In vivo experiments showed that the tumor volume of the Mito-FMIP-treated group was only one third of that of the untreated group. In addition, Mito-FMIP exibited the maximum emission wavelength at 682 nm, which allowed it to be used for fluorescence imaging of tumors. Taken together, this study provides a new strategy for the construction of nanomedicines with antimetabolic functions based on molecularly imprinted polymers.

In this work, we used a simple ultrasonic stripping method to synthesize a bimetal MOFs at room temperature as a nanoenzyme with peroxidase-like (POD-like) activity. Through bimetal MOFs catalytic Fenton-like competitive reaction, thiamphenicol can be quantitatively dual-mode detected by fluorescence and colorimetry. It realized the sensitive detection of thiamphenicol in water, and the limits of detection (LOD) were 0.030 nM and 0.031 nM, and the liner ranges were 0.1-150 nM and 0.1-100 nM, respectively. The methods were applied to river water, lake water and tap water samples, and with satisfactory recoveries between 97.67% and 105.54%., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The heat tolerance of tumor cells induced by heat shock proteins (HSPs) is the major factor that seriously hinders further application of PTT, as it can lead to tumor inflammation, invasion, and even recurrence. Therefore, new strategies to inhibit HSPs expression are essential to improve the antitumor efficacy of PTT. Here, we prepared a novel nanoparticle inhibitor by synthesizing molecularly imprinted polymers with a high imprinting factor (3.1) on the Prussian Blue surface (PB@MIP) for combined tumor starvation and photothermal therapy. Owing to using hexokinase (HK) epitopes as the template, the imprinted polymers could inhibit the catalytic activity of HK to interfere with glucose metabolism by specifically recognizing its active sites and then achieve starvation therapy by restricting ATP supply. Meanwhile, MIP-mediated starvation downregulated the ATP-dependent expression of HSPs and then sensitized tumors to hyperthermia, ultimately improving the therapeutic effect of PTT. As the inhibitory effect of PB@MIP on HK activity, more than 99% of the mice tumors were eliminated by starvation therapy and enhanced PTT.

Various physiological activities and metabolic reactions of cells need to be carried out under the corresponding pH environment. Intracellular GSH as an acid tripeptide and an important reducing substance also plays an important role in maintaining cellular acid-base balance and redox balance. Therefore, developing a method to monitor pH and GSH and their changes in cells is necessary. Herein, we developed a novel turn-on fluorescent silicon nanoparticles (SiNPs) using N -(2-aminoethyl)-3-aminopropyltrimethoxysilane as the silicon source and dithiothreitol as the reducing agent via a one-pot hydrothermal method. It was worth mentioning that the fluorescence intensity of the SiNPs increased along with the acidity increase, making the SiNPs have excellent pH and GSH sensing capability. Furthermore, the pH and GSH sensing performance of the SiNPs in the cell was verified by confocal imaging and flow cytometry experiment. Based on the above, the prepared SiNPs had the potential to be used as an intracellular pH and GSH multimode fluorescent sensing platform and exhibited the ability to distinguish between normal cells and cancer cells.

Chimeric antigen receptor-T (CAR-T) cell therapy based on functional immune cell transfer is showing a booming situation. However, complex manufacturing processes, high costs, and disappointing results in the treatment of solid tumors have limited its use. Encouragingly, it has facilitated the development of new strategies that fuse immunology, cell biology, and biomaterials to overcome these obstacles. In recent years, CAR-T engineering assisted by properly designed biomaterials has improved therapeutic efficacy and reduced side effects, providing a sustainable strategy for improving cancer immunotherapy. At the same time, the low cost and diversity of biomaterials also offer the possibility of industrial production and commercialization. Here, we summarize the role of biomaterials as gene delivery vehicles in the generation of CAR-T cells and highlight the advantages of in-situ construction in vivo . Then, we focused on how biomaterials can be combined with CAR-T cells to better enable synergistic immunotherapy in the treatment of solid tumors. Finally, we describe biomaterials' potential challenges and prospects in CAR-T therapy. This review aims to provide a detailed overview of biomaterial-based CAR-T tumor immunotherapy to help investigators reference and customize biomaterials for CAR-T therapy to improve the efficacy of immunotherapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Qin, Li, He, Wang, Li and Zhang.)

Chemodynamic therapy (CDT), the ability to transform H 2 O 2 into a highly toxic hydroxyl radical (˙OH) through a Fenton or Fenton like reaction to kill cancer cells, enables selective tumor therapy. However, the effect is seriously limited by the insufficiency of endogenous H 2 O 2 in cancer cells. Additionally, the specific recognition of epitope imprinting plays an important role in targeting cancer cell markers. In this work, we prepared H 2 O 2 self-supplying degradable epitope molecularly imprinted polymers (MIP) for effective CDT, employing fluorescent calcium peroxide (FCaO 2 ) as an imaging probe and a source of H 2 O 2 , the exposed peptide in the CD47 extracellular region as the template, copper acrylate as one of the functional monomers and N,N'-bisacrylylcystamine (BAC) as a cross-linker. MIP with recognition sites can specifically target CD47-positive cancer cells to achieve fluorescence imaging. Under the reduction of glutathione (GSH), the MIP were degraded and the exposed FCaO 2 reacted with water to continuously produce H 2 O 2 in the slightly acidic environment in cancer cells. The self-supplied H 2 O 2 produced ˙OH through a Fenton like catalytic reaction mediated by copper ions in the MIP framework, inducing cancer cell apoptosis. Therefore, the MIP nano-platform, which was capable of specific recognition of the cancer cell marker, H 2 O 2 self-supply and controlled treatment, was successfully used for targeted CDT.

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. Graphical abstract An oriented epitope imprinted polymer embedded with carbon dots was prepared for the determination of the epitopes of epidermal growth factor receptor and targeted fluorescence imaging of cervical cancer.

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., (Copyright © 2018 Elsevier B.V. All rights reserved.)

A novel dual-template epitope imprinting polymer coated on magnetic carbon nanotubes (MCNTs@D-EMIP) was successfully prepared for specific recognition of porcine serum albumin (PSA) via dual-template epitope imprinting, metal chelation imprinting and distillation-precipitation polymerization (DPP). C-terminal peptides and N-terminal peptides of PSA were selected as templates simultaneously, and zinc acrylate and ethylene glycol dimethacrylate (EGDMA) were used as functional monomer and cross-linker, respectively. The epitope templates were immobilized by metal chelation and six-membered ring formed with zinc acrylate. Finally, MCNTs@D-EMIP was synthesized by DPP in only 30 min, which was much shorter than those of other polymerization methods. The prepared MCNTs@D-EMIP displayed specific recognition ability toward PSA and its adsorption amount and imprinting factor were 45.05 mg g -1 and 4.50, which were much higher than those of single template epitope imprinting polymers. Besides, high-performance liquid chromatography (HPLC) analysis of PSA in porcine blood serum real sample indicated that the specificity was not affected by other competitive proteins, which forcefully stated that the MCNTs@D-EMIP had potential to be applied in bio-separation area. In addition, the results of cross-reactivity experiment proved that this strategy had generality to prepare dual-template epitope imprinting polymer for recognition of target protein. In summary, this study provided an efficient protocol to recognize target protein in complex sample via dual-template epitope imprinting approach, metal chelation imprinting and distillation-precipitation polymerization., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Silicon nanoparticles (Si NPs) have been widely used in fluorescence imaging. However, rigorous synthesis conditions and the single modality imaging limit the further development of Si NPs in the field of biomedical imaging. Here, we reported a method for synthesizing water-dispersible Mn 2+ functionalized Si NPs (Mn-Si NPs) under mild experimental conditions for fluorescence and magnetic resonance dual-modality imaging. The whole synthesis process was completed under room temperature and atmospheric pressure, and no special and expensive equipment was required. The synthetic nanoparticles, with favorable pH stability, NaCl stability, photostability, and low toxicity, emitted green fluorescence (512 nm). At the same time, the nanoparticles also demonstrated excellent magnetic resonance imaging ability. In vitro, their T 1 -weighted magnetic resonance imaging effect was obvious, and the value of longitudinal relaxation degree r 1 reached 4.25 mM -1 s -1 . On the basis of their good biocompatibility, Mn-Si NPs were successfully used for the fluorescence imaging as well as magnetic resonance imaging in vivo.

The present research proposed general evaluation strategy named Null-Test for peptide identification algorithm in Shotgun proteomics. The Null-Test method based on random matching can be utilized to check whether the algorithm has a tendency to make a mistake or has potential bugs, faultiness, errors etc., and to validate the reliability of the identification algorithm. Unfortunately, none of the five famous identification software could pass the most stringent Null-Test. PatternLab had good performance in both Null-Test and routine search by making a good control on the overfitting with sound design. The fuzzy logics based method presented as another candidate strategy could pass the Null-Test and has competitive efficiency in peptide identification. Filtering the results by appropriate FDR would increase the number of discoveries in an experiment, at the cost of losing control of Type I errors. Thus, it is necessary to utilize some more stringent criteria when someone wants to design or analyze an algorithm/software. The more stringent criteria will facilitate the discovery of latent bugs, faultiness, errors etc. in the algorithm/software. It would be recommended to utilize independent search combining random database with statistics theorem to estimate the accurate FDR of the identified results., Biological Significance: In the past decades, considerable effort has been devoted to developing a sensitive algorithm for peptide identification in Shotgun proteomics. However, little attention has been paid to controlling the reliability of the identification algorithm at the design stage. The Null-Test based on random matching can be utilized to check whether the algorithm has a tendency to make a mistake or has potential bugs, faultiness, errors etc. However, it turns out that none of the five famous identification software could pass the most stringent Null-Test in the present study, which should be taken into account seriously. Accordingly, a candidate strategy based on fuzzy logics has been demonstrated the possibility that an identification algorithm can pass the Null-Test. PatternLab shows that earlier control on overfitting is valuable for designing an efficient algorithm., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A novel fluorescent sensor nitrogen-doped graphene quantum dots (N-GQDs)/SiO 2 /molecular imprinting polymer（N-GQDs/SiO 2 /MIP）was fabricated by surface imprinting and epitope imprinting to recognize and detect the target protein cytochrome c (Cyt C) with fluorescence quenching. In the polymerization process, the C- and N-terminal nonapeptides of Cyt C were selected as the double templates which were fixed by functional monomer (zinc acrylate) through metal chelation and steady six-membered ring. The linear range of fluorescence quenching for this receptor towards Cyt C was 0.20-60μM, and the detection limit was 0.11μM. The precision for six times replicate determination of Cyt C at 30μM was 1.20%, and the imprinting factor (IF) was 3.06. The recoveries of the material to Cyt C in urine were 99.3-114.0%. In brief, this work proposed a strategy to prepare a new type fluorescent imprinting polymer based on N-GQDs and provided an attractive perspective for the detection of protein by using the combination of N-GQDs and molecular imprinting technique., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this study, a simple solid-phase extraction (SPE) approach by using activated attapulgite as sorbent was successfully developed for the determination of melamine in milk formula samples. Crucial factors impacting the extraction efficiency, including sample solvent, elution solvent, and sample loading volume, were investigated. Under the optimal extraction conditions, the sample loading volume was up to 200 mL and the adsorption capacity of the melamine gave rise to 1154 μg g(-1). Excellent linear calibration curves (r (2)  > 0.999) were achieved, and then the limit of detection (S/N = 3) and the limit of quantification (S/N = 10) were found to be 0.15 and 0.5 ng mL(-1), respectively. The recoveries of the melamine spiked in four milk formula samples at three concentration levels ranged from 83.5 to 111.0 % with relative standard deviations (RSDs) less than 10.2 %. Furthermore, RSDs of batch to batch (n = 4) of the acidified attapulgite used in this developed method were in the range of 2.3∼7.3 %. In comparison to the commercial Oasis MCX, the acidified attapulgite sorbent even outperformed (at least in terms of reproducibility) for melamine analysis in real food samples. Because of its simplicity, the newly developed SPE method based on acidified attapulgite nanoparticles should provide a promising tool for daily monitoring of doped melamine in milk formula or other complex matrices.

A new type of thermo-sensitive receptor carbon dots/SiO2/molecularly imprinted polymer (CDs/SiO2/MIP) was prepared by surface imprinting procedure and the epitope approach. The synthetic CDs/SiO2/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., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Glycosylation plays an important part in many biological processes. However, many glycoproteins are either of low abundance or covered by other components in biological samples. Hence, developing new methods to measure the glycoproteins with both high efficiency and low detection limit is important. In this work, a self-assembled 4-mercaptophenylboronic acid film was coated on a quartz crystal microbalance chip. By optimizing the reaction time and the concentration of 4-mercaptophenylboronic acid, a sensor that specifically responded to glycoproteins was created. Then, several parameters for the prepared sensor were investigated and the working curve for representative glycoprotein-transferrin was established. The linearity range was from 50 to 400 ng/mL and the detection limit was 21.0 ng/mL. The sensor was used to detect transferrin in artificial urine samples. This sensor has a low detection limit of glycoproteins requiring only a small amount of samples, and thus has potential applications in both pharmaceutical and medical areas.

The main objective of this study was to develop a new methodology for the preparation of a protein (antigen) that is a molecularly imprinted polymer (MIP, an artificial antibody) modified onto the surface of a silica skeleton in which the resulting stationary phase is thermosensitive. The silica monolithic skeleton with vinyl groups was synthesized in a stainless-steel column by using a mild one-step sol-gel process with two types of precursor: methyltrimethoxysilane (MTMS) and γ-methacryloxypropyltrimethoxysilane (γ-MAPS). Subsequently, three types of the thermosensitive protein MIP were anchored onto the surface of the silica skeleton to prepare the MIP monoliths, which were systematically investigated for back pressure and separation ability at different temperatures to establish good imprinting conditions. Under the optimized imprinting conditions, the chromatographic behavior of the thermosensitive MIP monolith exhibited strong retention ability for the lysozyme template (target antigen) in relation to the nonimprinting monolith (NIP monolith). The imprinting factor (IF) for lysozyme reached 3.48 at 20 °C. Moreover, this new type of artificial antibody displayed favorable binding characteristics for lysozyme over competitive proteins and was further evaluated to selectively separate lysozyme in a real sample by using an on-line method. The run-to-run and column-to-column repeatability measurements of the thermosensitive MIP monoliths were also satisfactory., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Aim: To prepare the recombinant epitopes of SARS-CoV spike protein and study their antigenic property to spike protein., Methods: The epitopes of SARS-CoV spike protein were analyzed by epitope prediction software. A novel gene, named Z, encoding 16 predicted epitopes of spike protein was designed and synthesized using chemical method. Z gene was cloned into vector pET-28a(+), expressed in E.coli BL21(DE3) and purified by Ni(2+) affinity method. Z protein was used as antigen to immunize the rabbit and anti-Z sera was collected. Then the antigenic property of Z protein to SARS-CoV spike protein was analyzed by dot-blot and ELISA assay., Results: Z gene was successfully designed and expressed in E.coli BL21(DE3). Dot blot analysis showed that SARS-CoV spike protein, which was expressed and purified from mammal cells, can be detected by anti-Z sera from rabbit. ELISA analysis indicated the SARS-CoV antigen prepared from SARS-CoV lysates can be detected by anti-Z sera., Conclusion: The predicted epitopes of Z protein can induce the development of SARS-CoV spike protein antibody in rabbits, which provides a new protein for developing vaccine against SARS-CoV.

In this report, a novel preparation method of molecularly imprinted polymers (MIPs) for CEC was developed. Molecularly imprinted monolithic columns for (S)-ibuprofen were prepared and evaluated, in which charged entities responsible for establishing EOF have been derived from gamma-methacryloxypropyltrimethoxysilane (gamma-MAPS), which was hydrolyzed following copolymerization with 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate (EDMA). The EOF and molecular recognition of the stationary phase were investigated in aqueous and nonaqueous media, respectively. The experimental results indicated that the material showed a reasonably stable EOF and the prepared separation materials were capable of separating racemic ibuprofen, a task that could not be accomplished by MIPs prepared in parallel, using methacrylic acid (MAA) as a functional monomer. The efficiency at pH 3.2 for the first-eluted enantiomer and the last-eluted enantiomer (the imprinted analyte) were 128,700 and 2100 plates/m, respectively.

Aim: To study the MS/MS fragmentation mechanism of Taxol, and based on it to establish HPLC-ESI-MS/MS technique to separate and identify Taxol in the crude extracts of Taxus cuspidata and its callus culture, consequently to provide a fast and credible method for the analysis of Taxol in natural products., Methods: Optimized the HPLC-ESI-MS/MS parameters for the sample analysis, and then discussed the ionization and cleavage mechanism of Taxol in ESI-MS and ESI-MS/MS, finally identified the Taxol in the samples with retention time, molecular weight and MS/MS spectra., Results: Elucidated the MS/MS fragmentation mechanism of Taxol, and developed HPLC-ESI-MS/MS method to analyze Taxol in the two samples., Conclusion: The HPLC-ESI-MS/MS method is rapid, highly sensitive and specific, so it is suitable for the separation and identification of Taxol in natural products.

In order to fabricate the HLA-DQA1 genotyping chip and develop an integrated, parallel technical platform to type HLA system, a pair of primers and a set of probes were designed according to the sequences of HLA-DQA1 exon 2, where the polymorphism is concentrated. The oligonucleotide chip was made with the methods developed in our laboratory. The target DNA was asymmetrically amplified with the labeled sense primer. The signals were scanned and analyzed after the hybridization between microarray and PCR product. The allele types of the samples were identified. The result was verified by the standard DNA and DNA sequencing. The results showed that the genotyping was successfully carried out in 50 standard DNA samples and 50 clinical samples. Among them, results of the 50 standard DNA samples matched their templates. In the other 50 samples, results of the randomly selected 10 matched their sequencing results except that two of them got the incompletely result. In reproducible tests, the signal reappear rate was 95%. It is concluded that HLA-DQA1 genotyping by using our array system is simple and convenient with satisfied accuracy and reproducibility.

Oligochitosan is an effective inductor for plant resistance. To understand the induced resistance mechanism, mRNA differential display was used to isolate genes from Nicotiana tabacum var. Samsun NN and four enhanced-expression gene fragments were obtained and were reamplified. The reamplified products of appropriate size were isolated and purified before they were subcloned into PMD18-T vector. The results of plasmids digestion by EcoRI and HindIII and analysis of reverse Northern blot indicated that the expression of the four genes was enhanced by oligochitosan induction. Sequence and homology analysis show that they share 82% identity in nucleotide sequence with Nicotiana benthamiana SKP1 gene. Because the SKP1 protein as the core component of SCF (ubiquitin ligase enzyme E3) is relevant to plant resistance to virus, so these results suggested that oligochitosan can induce plant resistance and its mechanism may be relevant to ubiquitination.

Aim: To detect the variations of mitochondrial 12S rRNA in patients with gastric carcinoma, and to study their significance and the relationship between these variations and the genesis of gastric carcinoma., Methods: PCR amplified mitochondrial 12S rRNA of 44 samples including 22 from gastric carcinoma tissues and 22 from adjacent normal tissues, was detected by direct DNA sequencing. Then laser capture microdissection technique (LCM) was used to separate the cancerous cells and dysplasia cells with specific mutations. Denaturing high performance liquid chromatography (DHPLC) plus allele-specific PCR (AS-PCR), nest-PCR and polyacrylamide gel electrophoresis (PAGE) were used to further evaluate this mutant property and quantitative difference of mutant type between cancerous and dysplasia cells. Finally, RNAdraw biosoft was used to analyze the RNA secondary structure of mutant-type 12S rRNA., Results: Compared with Mitomap database, some new variations were found, among which np652 G insertion and np716 T-G transversion were found only in cancerous tissues. There was a statistic difference in the frequency of 12S rRNA variation between intestinal type (12/17, 70.59%) and diffusive type (5/17, 29.41%) of gastric carcinoma (P<0.05). DHPLC analysis showed that 12S rRNA np652 G insertion and np716 T-G transversion were heteroplasmic mutations. The frequency of 12S rRNA variation in cancerous cells was higher than that in dysplasia cells (P<0.01). 12S rRNA np652 G insertion showed obviously negative effects on the stability of 12S rRNA secondary structure, while others such as T-G transversion did not., Conclusion: The mutations of mitochondrial 12S rRNA may be associated with the occurrence of intestinal-type gastric carcinoma. Most variations exist both in gastric carcinomas and in normal tissues, and they might not be the characteristics of tumors. However, np652 G insertion and np716 T-G transversion may possess some molecular significance in gastric carcinogenesis. During the process from normality to dysplasia, then to carcinoma, 12S rRNA tends to convert from homoplasmy (wild type) to heteroplasmy, then to homoplasmy (mutant type, np717 T-G).

Aim: To explore the instabilities, polymorphisms and other variations of mitochondrial D-loop region and downstream gene 12S rRNA-tRNA(phe) in gastric cancers, and to study their relationship with gastric cancer., Methods: Three adjacent regions (D-loop, tRNA(phe) and 12S rRNA) were detected for instabilities, polymorphisms and other variations via PCR amplification followed by direct DNA sequencing in 22 matched gastric cancerous tissues and para-cancerous normal tissues., Results: PolyC or (CA) (n) instabilities were detected in 13/22(59.1 %) gastric cancers and 9/22(40.9 %) in the control (P>0.05). There existed 2/12(16.7 %) and 6/10(60 %) alterations of 12S rRNA-tRNA(phe) in well differentiated gastric cancers and poorly differentiated ones, respectively (P<0.05). Some new variations were found, among which np 318 and np 321 C-T transitions in D-loop region were two of the five bases for H-strand replication primer. np 523 AC-deletion and np 527 C-T transition occurred at mtTF1 binding site (mtTFBS), which were associated with the transcription of downstream mitochondrial genome. Seven samples showed the np 16 182 polyC instabilities, five of which simultaneously showed np 16 189 T-C transitions., Conclusion: There is no statistic significance of instabilities and polymorphisms in mitochondrial D-loop region between gastric cancerous and para-cancerous normal tissues, which suggests that the instability might relate to heredity or be dependent on aging. There is a significant correlation between differentiation degree of gastric cancer and variant frequencies of 12S rRNA-tRNA(phe). The poorly differentiated gastric cancers are more prone to 12S rRNA-tRNA(phe) variations, or gastric cancers with 12S rRNA-tRNA(phe) variations are more likely to be poorly differentiated. np 16 189 T-C transition may be one of the important reasons for polyC instability in gastric cancer.

To optimize and screen the most suitable target gene length,concentration and printing solution in cDNA microarray, housekeeping genes, such as beta actin and GAPDH, were selected as targets and hepatitis B virus gene as negative control. The RT-PCR primers that spanned at least one intron and whose products were at between 189 bp and 1078 bp were designed with primer premier 5.0, so did the hepatitis B virus gene PCR primer. After polymerase chain reaction, the products were purified with ethanol and dissolved in 3xSSC, 50% DMSO and 0.5 mol/L carbonate buffer(pH=9.0)respectively. The concentrations of target genes were adjusted at 0.5 microg/microL, 1.0 microg/microL and 1.5 microg/microL. The hybridization signals had a good specificity. No signal showed in either negative control (HBV) or blank control (printing solution only). There was no significant difference in target gene lengths. The P value of beta actin (189 bp,491 bp,974 bp) and GAPDH (227 bp,552 bp,1078 bp) was 0.378 and 0.866 respectively. There was no significant difference among concentrations(P=0.648),too. However, the higher the concentration was, the stronger the signals would be. Among the three kinds of printing solution, 50% DMSO was the best (P=0.0001), while the other two had no difference by multi-comparison (P=0.142). The target gene at length between 200 bp and 1000 bp has got the same hybridization signals.50% DMSO printing solution and the target gene concentration of 0.5 microg/microl are suitable for good hybridization.

Objective: To study the relationship between hRad17 mRNA expression and clinicopathologic factors and lymph node metastasis of gastric cancer, and to assess the significance of predicting the extent of lymph node metastasis and prognosis., Methods: hRad17 mRNA expression was examined in matched primary lesions, normal gastric mucosa and lymph node metastatic lesions among 52 gastric cancer patients by reverse transcription polymerase chain reaction (RT-PCR), polyacrylamide gel electrophoresis (PAGE) and silver stain with the relation between hRad17 mRNA expression and clinicopathologic factors analyzed. At the same time, hRad17 mRNA expressions in 5 gastric benign lesions and SGC7901 gastric carcinoma cell lines were also examined., Results: The primary tumor samples (88.4% positive) showed a significantly higher level of hRad17 expression compared with matched normal tissue (76.9% positive) (P = 0.014), so did the lymph node metastatic samples (94.2% positive) (P = 0.001). The hRad17 mRNA expression showed a low level in benign lesions, but very high in SGC7901 cell line. The hRad17 mRNA expression showed a higher level in patients with the number of lymph node metastasis above 15 than below 15 (P = 0.02), so did the diffused growth than the mass-like growth (P = 0.04)., Conclusion: The method of PAGE and silver stain can improve the sensitivity of RT-PCR. The degree of lymph node metastasis and invasiveness of carcinoma cells are more serious in cases with hRad17 mRNA overexpression, and extensive lymph node dissection should be carried out for these patients. Examination of hRad17 expression by RT-PCR before surgery is indicated to arrive at an optimum treatment scheme and to estimate the prognosis.

Monolithic columns of capillary electrochromatography (CEC) with low electroosmotic flow (EOF) have been prepared by in-situ polymerization of butylmethacrylate and ethylene dimethacrylate, without any charged groups existed in the reaction mixture. The good reproducibility of the columns has been proved no matter if they are prepared in the same or different batches. Besides the traditional ternary porogenic mixture of 1-propanol, 1,4-butanediol and water, a binary porogenic mixture with only alcohols has also been adopted. In comparing with the ternary porogenic mixture, the design of binary mixture allows fine control of pore diameter and the formation of specific surface of the monolithic polymers. The effects of composition and ratio of porogenic reagents on EOF of the column systems have also been shown. The pore properties and EOF of monolithic columns with different porogenic mixtures were investigated. The results of scanning-electron micrograph show that the continuous beds were quite different from each other, while the proportions of 1-propanol were the same under these two situations. In addition, the Joule heat effect of such columns has been studied by varying the inner diameter of capillary columns. The effect of length of capillary on the EOF was also studied. Under the conditions of high pH and high concentrations of organic solvents, low EOF was obtained to satisfy different needs from the diversified separation modes. Through the separation of acidic compounds, monolithic columns with low EOF have shown potentialities in the analysis of charged samples.

In capillary electrochromatography with the mixed-mode stationary phase, while the transfer of solutes could be controlled by the contributions of chromatography (reversed-phase and ion exchange), the transfer of charged solutes could be influenced by electrophoresis transfer. According to the principle of ion independent transfer and several kinds of interaction between solute, mobile phase, and stationary phase, an theoretical expression was derived to describe the relationship among the apparent transfer velocity of solute, the transfer velocities in various forms and the diversified interactions. The studies focused on the influence of various parameters (e.g., pH, organic modifier content, stationary phase proportion) and the transfer characters of various solutes in the mixed-mode capillary electroosmotic chromatography (CEC). These results demonstrate that electroosmotic flow in the mixed stationary phase electrochromatography are kept high and steady within wide ranges of pH and organic modifier content. The separation was affected by the pH through the change of the solutes conformation. The influence of neutral solutes by organic modifier complies with the rule of conventional reversed-phase CEC. The separation of charged solutes was influenced evidently by the compete reagents which could improve the shape of the peak, but it was not so important as in the conventional ion exchange chromatography due to the adjustment by the function of electrophoresis.

In high performance liquid chromatography, it is necessary to apply multi-composition gradient elution for the separation of complex samples such as environmental and biological samples. Multivariate stepwise gradient elution is one of the most efficient elution modes, because it combines the high selectivity of multi-composition mobile phase and shorter analysis time of gradient elution. In practical separations, the separation selectivity of samples can be effectively adjusted by using ternary mobile phase. For the optimization of these parameters, the retention equation of samples must be obtained at first. Traditionally, several isocratic experiments are used to get the retention equation of solute. However, it is time consuming especially for the separation of complex samples with a wide range of polarity. A new method for the fast optimization of ternary stepwise gradient elution was proposed based on the migration rule of solute in column. First, the coefficients of retention equation of solute are obtained by running several linear gradient experiments, then the optimal separation conditions are searched according to the hierarchical chromatography response function which acts as the optimization criterion. For each kind of organic modifier, two initial linear gradient experiments are used to obtain the primary coefficients of retention equation of each solute. For ternary mobile phase, only four linear gradient runs are needed to get the coefficients of retention equation. Then the retention times of solutes under arbitrary mobile phase composition can be predicted. The initial optimal mobile phase composition is obtained by resolution mapping for all of the solutes. A hierarchical chromatography response function is used to evaluate the separation efficiencies and search the optimal elution conditions. In subsequent optimization, the migrating distance of solute in the column is considered to decide the mobile phase composition and sustaining time of the latter steps until all the solutes are eluted out. Thus the first stepwise gradient elution conditions are predicted. If the resolution of samples under the predicted optimal separation conditions is satisfactory, the optimization procedure is stopped; otherwise, the coefficients of retention equation are adjusted according to the experimental results under the previously predicted elution conditions. Then the new stepwise gradient elution conditions are predicted repeatedly until satisfactory resolution is obtained. Normally, the satisfactory separation conditions can be found only after six experiments by using the proposed method. In comparison with the traditional optimization method, the time needed to finish the optimization procedure can be greatly reduced. The method has been validated by its application to the separation of several samples such as amino acid derivatives, aromatic amines, in which satisfactory separations were obtained with predicted resolution.

The separation mechanism for neutral solutes on a cyano column in capillary electrochromatography (CEC) was investigated and the effects of components of mobile phases and the kinds of buffers on retention of samples were studied. In comparing the separation behavior of samples on CN column with reversed-phase ODS column and normal phase SI column, the peak order was different on CN column under different experimental conditions, and the characteristics of CN column having both reversed and normal phase mechanisms were obvious. The migration velocities for neutral solutes of different polarity on CN column were very different by the effects of two mechanisms under different operating conditions. It is easy to change peak order and to adjust selectivity.