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MicroRNA is regarded as a significant biomarker for cancer diagnosis, disease process evaluation and therapeutic guidance, and dual-parameter measurement may contribute to a more accurate and realistic assessment. To meet the urgent need for simultaneous detection of multiple biomarkers, we combined three-dimensional DNAzyme motors with single molecule imaging technique to construct a convenient, intuitive, and sensitive approach for the simultaneous detection of dual miRNAs in the free state or in extracellular vesicles. Quantification of target miRNAs can be realized through the detection of amplified fluorescence signals generated by the target miRNA-initiated cleavage of fluorescent substrate strands by the DNAzyme motors. The practicability was systematically validated with microRNA-21-5p and microRNA-10b-5p as targets, acquiring a satisfactory sensitivity sufficient to detect low abundance targets at 0.5 or 1 pM to 100 pM. Besides, the extracellular vesicular miRNAs can be conveniently detected without extraction. The clinical applicability was verified with a series of extracellular vesicles from clinical samples, which exhibited good distinguishability between colorectal cancer patients and healthy donors. In addition to the advantages of good specificity and high sensitivity, the system has potential to be easily adapted by minor alteration of the DNA sequences and fluorophore sets for detection of multiple miRNAs and even other types of biomarkers such as proteins. Therefore, it shows promise to be widely applied in various fields such as early diagnosis of cancer and its prognostic assessment. [ABSTRACT FROM AUTHOR]

Two novel alkaline-earth zincophosphites, namely CaZn(HPO3)2 and Ba2Zn(HPO3)3, were successfully synthesized under hydrothermal conditions. CaZn(HPO3)2 exhibits a three-dimensional (3D) anionic framework with a 6-connected uni-nodal pcu α-Po primitive cubic topology, constructed by unique Zn2O8 dimers and HPO3 pseudo-tetrahedra, while Ba2Zn(HPO3)3 displays one-dimensional (1D) [Zn(HPO3)3]4− anionic chains. It is worth mentioning that CaZn(HPO3)2 represents the first example of an alkaline-earth zincophosphite compound with a 3D framework structure. Our research also revealed the importance of both alkaline earth cation sizes and Zn/P ratios in anionic open-framework formation. The crystal structures of both compounds were further verified by energy dispersive spectroscopy, IR spectroscopy and Raman spectroscopy. Optical diffuse reflectance spectra, coupled with Tauc's fitting, revealed direct bandgaps with energy values of 4.33 and 4.48 eV for CaZn(HPO3)2 and Ba2Zn(HPO3)3, respectively, which differ from the prediction of theoretical calculations. Density of states calculations were conducted to reveal the origin of the bandgaps and bond interactions. Both compounds exhibited moderate birefringence values. This work may have implications for the design and synthesis of novel metal phosphites with desired properties. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) are composed of asymmetric cationic and anionic moieties and are used as green solvents. Their non-toxic nature, favorable biocompatibility and adjustable structure facilitate wide biomedical applications. ILs promote the generation of various nanohybrids that exhibit multiple functions and novel/improved properties with respect to their precursors. Generally, nanostructures have a large specific surface area and abundant functional groups which enable loading and incorporation of ILs through physical interactions or chemical bonding. According to their main skeleton structures, IL-based nanohybrids may be divided into five categories, i.e., poly(ionic liquid)s (PILs), IL-inorganic nanohybrids, IL-metal organic framework nanohybrids (IL-MOF nanohybrids), ILs/carbon materials and ionic materials. These IL-based nanohybrids exhibit various specific features, including thermal responsive behavior, metal chelating, photothermal conversion and antibacterial capabilities. Taking advantage of these characteristics, IL-based nanohybrids may overcome the shortcomings of conventional medicines/drugs and exhibit promising prospects in biomedicine to facilitate controlled drug release, bactericidal treatment and thermotherapy. The present review presents the state-of-the-art progress made in the studies of IL-based nanohybrids in terms of their classifications, structure characteristics, versatile functionalities and biomedical and pharmaceutical applications. The challenges and future perspectives in the developments and applications of IL-based nanohybrids in biomedicine are discussed. [ABSTRACT FROM AUTHOR]

TMR-TPE, a ratiometric fluorescent probe, was reported for the imaging of vicinal dithiol proteins (VDPs) in living cells. Profiting from the "dual-key-and-lock" design, TMR-TPE solves the toxicity problem of VDP probes (98% cell viability at 50 μM) and avoids the interference of small thiols (up to 10 mM GSH). The change of VDPs during drug-induced liver injury was monitored for the first time using TMR-TPE. [ABSTRACT FROM AUTHOR]

In aptamer-based assay schemes, aptamer probes not labeled with biomarkers have to be eliminated before testing, which may lead to a tremendous waste of precious probes. We herein propose a microfluidics system integrating an aptamer concentration gradient generator (Apt-CGG) and a dual single-cell culturing array (D-SCA), termed Mi-Apt-SCA. This facilitates the precise construction of a nanoscale-gradient microenvironment and the high-throughput profiling of single-cell growth/phenotypes in situ with the minimal consumption of Apt-probe. Unlike previous snakelike mixers, the choreographed winding-ravined aptamer dual-spiral micromixer (Apt-WD-mixer) in Apt-CGG could allow thorough blending to generate linear concentration gradients of aptamer (quasi-non-Newtonian fluid) under the action of continuous fluidic wiggles and bidirectional Dean flow. In contrast to other trap-like systems, the mild vortex allows single-cell growth in an ultra-tender fluidic microenvironment using triple-jarless single-cell culture capsules (TriJ-SCCs) in D-SCA (shear stress: 3.43 × 10−5 dynes per cm2). The minimum dosage of aptamer probe required for exploring PDL1 protein expression in two hepatoma cell lines is only one-900th of that required by conventional protocols. In addition, this approach facilitated the profiling of ITF-β/cisplatin-mediated single-cell/cell-cluster phenotypes. [ABSTRACT FROM AUTHOR]

Acetylcholinesterase (AChE) is an essential serine hydrolase associated with neurodegenerative diseases and serves as a biomarker. In this work, a ratiometric fluorescence strategy for the sensitive assay of AChE activity is developed based on the decomposition of MnO2 by the enzymatic hydrolysis product and DNAzyme-mediated strand cleavage. The sensing system is termed as MnO2/DNAzyme. DNAzyme locked by H2 strands is inactive in the absence of AChE. The fluorescence emission of fluorescein amidite (FAM)-labeled DNA (DNA-F) at 518 nm is quenched by neutral red (NR) and the fluorescence of NR at 632 nm is simultaneously enhanced due to fluorescence resonance energy transfer (FRET). The presence of AChE triggers the hydrolysis of the substrate acetylcholine (ATCh) to enzymatic thiocholine (TCh), which reduces MnO2 nanowires to Mn2+ and releases the attached H1 strands into the solution. The H1 strands hybridize with H2 strands through the strand displacement reaction. Meanwhile, the activated DNAzyme cleaves the RNA nucleotide of the DNA-F signal probe to release FAM. The fluorescence of FAM at 518 nm is thus recovered, corresponding to a decrement of NR emission at 632 nm owing to the blocking of FRET. The fluorescence ratio of F518/F632 serves as a signal readout for the AChE assay within 5 × 10−4–10 U mL−1, with a limit of detection (LOD) of 2.7 × 10−4 U mL−1. The feasibility of this method was demonstrated by the measurement of AChE activity in human blood, which reveals its promising potential in clinical assays. [ABSTRACT FROM AUTHOR]

The measurement of ultra-trace levels of heavy metals in complex matrices is of great concern and challenge in life and environmental science. Herein, a novel thiol-functionalized covalent organic framework (COF) was prepared, and quantitative preconcentration of trace heavy metals in environmental water samples was achieved. The material was synthesized by a two-step reaction, including a Schiff base reaction between 1,3,5-triformylphloroglucinol (Tp) and 2,5-divinyl-p-phenylenediamine (DvPa) to form a preliminary COF (TpDvPa), and a thiol–ene "click" reaction between 1,2-ethanedithiol and the vinyl groups of TpDvPa to produce thiol-functionalized TpDvPa (TpDvPa-S-SH). By packing the material into a home-made SPE micro-column, and hyphenating the micro-column with inductively coupled plasma mass spectrometry (ICP-MS), trace levels of Co2+, Ni2+ and Cd2+ in environmental waters could be successfully preconcentrated and measured, with limits of detection of 1.46, 1.38 and 0.10 ng L−1, respectively. The precisions were all less than 2.7%, with linear ranges extending from 5 to 1000 ng L−1. The proposed method was validated by the analysis of the certified reference material (GBW08608), and measurement of Co2+, Ni2+ and Cd2+ in tap water, reservoir water, effluent of a wastewater treatment plant and sea water, confirming the accuracy and feasibility of the method. [ABSTRACT FROM AUTHOR]

Terbium doped graphitic carbon nitride (g-C3N4:Tb) gives rise to two exceptional emissions at λex/λem = 290/490 nm and 290/546 nm, with extremely narrow peak widths of FWHM < 12 nm as well as a large Stokes shift of >200 nm. The modification of g-C3N4:Tb with HOOC–PEG–COOH provides a ratiometric fluorescent probe which ensures highly sensitive detection of alkaline phosphatase (ALP) activity based on the inner filter effect (IFE). [ABSTRACT FROM AUTHOR]

As an indispensable biothiol, cysteine (Cys) plays a critical part in cellular redox homeostasis, and pathological and physiological processes. One of the main sources of reactive oxygen species (ROS) in human cells is the substrate end of the respiratory chain in the mitochondrial inner membrane. Therefore, it is valuable to develop probes targeting mitochondria to detect Cys. In this work, we designed a novel fluorescent probe, 2-(2-(6-(acryloyloxy) naphthalen-2-yl) vinyl)-3-ethylbenzothiazol-3-ium (ANET). The naphthyl benzothiazole is the fluorophore group and the acrylate moiety is the Cys response site to avoid the interference of homocysteine (Hcy) and glutathione (GSH). ANET combines multiple strengths for detecting Cys: targeting mitochondria, ratiometric fluorescence, high selectivity, and a large Stokes shift. After ANET reacted with Cys, the fluorescence signals changed from green (λem = 525 nm) to orange red (λem = 595 nm), and the detection limit was calculated to be 74 nM through a linear relationship between ratiometric fluorescence F595/F525 and Cys concentration. The imaging of Cys was confirmed in HepG2 cells. [ABSTRACT FROM AUTHOR]

Lacunary polyoxometalate (POM), [PW9O34]9−, grafts with a boronic acid group attached via an organosilane bridge assemble into microspheres, PW9–Si–APBA. The oxygen-rich and hydrophilic surface of POM facilitates the binding of phosphate groups in phosphoproteins and glycans in glycoproteins. While the metal–oxo in POM provides π–π interactions with the phosphate groups of phosphoproteins, the boronic acid group specifically binds to glycoproteins via the cis-diols of glycans. Therefore, these multi-driving forces ensure the selective adsorption of phosphoproteins and glycoproteins by PW9–Si–APBA microspheres in biological sample matrixes, even in the presence of very high protein abundance, i.e., BSA, at mass ratio of β-ca/IgG/OVA/BSA = 1 : 1 : 1 : 200. [ABSTRACT FROM AUTHOR]

A quantitative imaging strategy for the vicinal dithiol (VD) of arsenic-binding proteins in the mouse brain is reported. 2-p-Aminophenyl-1,3,2-dithiarsenolane (PAO-EDT) couples to gold nanoclusters Au22(GSH)18 to form conjugate Au22-PAO-EDT (APE). PAO-EDT in APE selectively binds VD with 1 : 1 stoichiometry. After tagging the mouse brain with APE, VD imaging is realized by laser ablation ICP-MS. VD correlates linearly with 197Au in APE offering a 22-fold amplification and a LOD of 5.43 nM. It is found that the cerebral cortex and hippocampus are most affected in an arsenic poisoned mouse brain. This study provides useful information for further understanding the mechanisms underlying the biological effects of arsenic on the living body. [ABSTRACT FROM AUTHOR]

A hierarchical multichannel polydopamine (HMPDA) nanoparticle with ample chondroitin sulfate (CS) is fabricated via modification of the silane coupling agent (APTES), followed by grafting CS on the unique bicontinuous open channels of HMPDA through amidation reaction. The obtained nanoparticles with both mesopores and macropores, abbreviated as HMPDA-A-CS15, possess a total pore volume of 0.3398 cm3 g−1, and a large surface area up to 69.10 m2 g−1. The as-prepared HMPDA-A-CS15 exhibits significantly enhanced selectivity for the separation of LDL, which is attributed to the specific recognition effect of CS for LDL. Furthermore, the unique large open channels endow the HMPDA-A-CS15 nanoparticles with a gratifying sorption capacity (1015.2 mg g−1) for LDL adsorption. The captured LDL can be stripped using 0.5% (v/v) ammonia solution with the advantage of easy atomization in downstream mass spectrometry (MS) analyses, and a recovery of 71.7% is achieved. Moreover, HMPDA-A-CS15 is further employed in the enrichment of LDL, which can be separated from the complex serum of simulated hypercholesterolemia patients with a favorable adsorption performance, as illustrated by the SDS-PAGE technique. [ABSTRACT FROM AUTHOR]

In recent years, α-glucosidase inhibitors (AGIs) have played a significant role in the treatment of type II diabetes (T2D), so it is necessary to develop a reliable and sensitive method to find new AGIs. Herein, we establish a novel method based on fluorescent carbon nitride nanoparticles (CNNPs) for the sensitive detection of the activity of α-glucosidase (α-glu) and the screening of its inhibitors. A CNNP-based fluorescent probe is synthesized from green raw materials, urea and lysine, by a one-pot method. In the presence of α-glu, the substrate 4-nitrophenyl-α- D -glucopyranoside (pNPG) is hydrolyzed to generate 4-nitrophenol (pNP), leading to the fluorescence (FL) quenching of CNNPs due to the inner filter effect (IFE). On the other hand, the activity of α-glu is inhibited after the addition of AGIs, which turns on the FL of CNNPs. In this way, the detection of α-glu activity and the screening of AGIs are achieved. The linear range is 1.25–10.00 U L−1 with a limit of detection as low as 0.17 U L−1 and the IC50 values of two typical inhibitors (gallic acid and acarbose) are 813 μM and 465 μM, respectively. The CNNP probe is further applied for the determination of α-glu activity in human serum samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Chemodynamic therapy (CDT) is a new emerging strategy for the in situ treatment of tumors. In the microenvironment of tumor cells, CDT may be achieved through the generation of reactive oxygen species (ROS), e.g., hydroxyl radicals (˙OH) and singlet oxygen (1O2), which induce the death of tumor cells. Copper (Cu) or other transition-metal ions catalyze the production of ˙OH by hydrogen peroxide (H2O2) through Fenton or Fenton-like reactions. With the development of advanced nanotechnology, nanotherapeutic systems with Cu-based nanostructures have received extensive attention and have been demonstrated for their wide applications in the design and construction of nanotherapeutic systems for CDT, along with multimodal synergistic therapy. Herein, the cutting-edge developments of Cu-based nanostructures in CDT are reviewed and discussed, by focusing on the monotherapy of CDT as well as synergistic treatments by hyphenating CDT with various therapeutic protocols, e.g., photothermal therapy (PTT), photodynamic therapy (PDT), sonodynamic therapy (SDT), and so on. In addition, the potential challenges and future perspectives are described in the improvement of CDT therapeutic efficacy, the enhancement of targeting capability, and mechanistic investigations on CDT therapy. [ABSTRACT FROM AUTHOR]

Redox cyclings between mono-/di-valent copper oxidation states occur in electron transfer reactions that underlie their biological functions. We report herein a dual channel fluorescent nanoprobe for the detection of mono- and di-valent copper ions. The probe, BSA-CDs@RBH/BCS, is designed by decorating carbon dots (CDs) on BSA encapsulated rhodamine hydrazide (RBH) and conjugating with bathocuproine disulfonate (BCS). Cu2+ catalyzes the hydrolysis of RBH, and the formed rhodamine B (RhB) shows emission at λex/λem = 360/575 nm which ensures Cu2+ detection. BSA reduces Cu2+ to Cu+ and the BCS–Cu+ chelate shows emission at λex/λem 360/450 nm which ensures Cu+ assay. Thus, the dual-channel fluorescence enables speciation of Cu2+ and Cu+. [ABSTRACT FROM AUTHOR]

Herein, novel carbon dots (CDs) with efficient antibacterial activity are prepared by a simple cyclization reaction of 4-formylbenzoic acid and pyrrole and cross-linking with p-phenylenediamine at room temperature. The CDs exhibit the fluorescence property of red emission, greatly reducing the noise interference from bacterial autofluorescence in fluorescence imaging. At the same time, the CDs with the feature of red absorption facilitate the achievement of light excitation of deep tissues in the living body. Owing to the introduction of the porphyrin ring structure as a photosensitizer, the CDs are able to trigger the generation of singlet oxygen. When excited by a 638 nm laser and irradiated for 20 min, 10 μg mL−1 CDs can achieve complete bacterial extinction. Laser confocal microscopy imaging further demonstrates that the CDs act on the outside of bacteria and generate reactive oxygen species under red light irradiation, providing a non-multidrug resistant sterilization method. [ABSTRACT FROM AUTHOR]

The number and arrangement of arginine (Arg) residues in protein chains contribute greatly to the selective capturing of proteins on a designed adsorbent consisting of organic phosphate functionalized fibrous SiO2 microspheres, and the efficient depletion of high abundance Arg-rich protein species from human plasma is achieved. [ABSTRACT FROM AUTHOR]

Glycoproteins always participate in various biological processes. Selective separation and enrichment of glycoproteins are of great significance for the research of pathogenesis. Herein, macroporous polymer microspheres were fabricated, and further functionalized by polyoxometalate. Thus, a simple, efficient and highly selective approach was constructed for glycoprotein enrichment from a complex matrix. The as-prepared material shows promise as a potential adsorbent in bio-separation and downstream clinical applications. [ABSTRACT FROM AUTHOR]

Mercury speciation is of significant importance in environmental and biological analysis because its toxicity and metabolic behavior in the human body differ among species. Nanomaterial-assisted optical sensors are widely used for mercury ion detection but rarely applied in mercury speciation analysis. In this work, we develop a novel colorimetric sensing strategy for mercury speciation based on mercury-stimulated peroxidase mimetic activity of gold nanoparticles with the assistance of different reductants. In the presence of a weak reductant, only inorganic mercury can be reduced to Hg0, whereas both inorganic mercury and organic mercury can be reduced to Hg0 in the presence of a strong reductant. Due to the high affinity between Hg and Au, Hg0 deposits on the AuNP surface in the form of a Au–Hg amalgam, leading to a remarkable enhancement of peroxidase mimetic activity of gold nanoparticles. On the basis of this effect, inorganic mercury and total mercury can be detected by using 3,3′,5,5′-tetramethylbenzidine (TMB) as the substrate. The limits of detection for inorganic mercury and total mercury are 1.9 and 0.9 nM within 5–100 nM, respectively. The selectivity of this sensing system is high due to the specificity of Au–Hg interaction. Its practical applications are further demonstrated by organic mercury analysis in a fish sample and mercury speciation in a human hair sample. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks functionalized with Cd(II) binding phages were for the first time fabricated for the isolation and preconcentration of ultra-trace cadmium. Highly specific Cd(II) binding phages were screened through biological panning from a phage display peptide library. Thereafter, chloroauric acid (HAuCl4) was reduced by the phages to provide phage-stabilized gold nanoparticles (AuNPs). The phage-AuNP networks were then assembled onto the metal–organic framework UiO66-NH2 to serve as an affinity probe for the selective recognition and isolation of ultra-trace cadmium. 2.0 μg L−1 Cd2+ was selectively captured by the derived UiO66-NH2@phage composite with an adsorption efficiency of 100%. UiO66-NH2@phage exhibits favorable anti-interference capability against the coexisting species. It ensures highly selective and sensitive quantification of ultra-trace cadmium with detection by graphite furnace atomic absorption spectrometry (GFAAS). An enrichment factor of 17.4 was obtained along with a limit of detection (LOD) of 3.9 ng L−1 within a linear range of 0.01–0.35 μg L−1. The procedure was further validated by analyzing cadmium content in a certified reference material (CRM, simulated water, GBW08608) and a series of environmental water samples. In general, the present study provides a new protocol for the development of novel adsorbents toward the target by biopanning to regulate the selectivity. [ABSTRACT FROM AUTHOR]

We constructed a carbon-based polymer dot (CPD) sensor to detect breast cancer based on the differences of peripheral blood cells, providing a new minimally invasive method for cancer diagnosis. This simple and extensible system exhibits clinically relevant accuracy in terms of cancer identification, making it an attractive strategy for diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

In this study, CuS@PDA nanoparticles were synthesized and used to create a novel tumor-targeting nanocomposite platform composed of copper sulfide@polydopamine–folic acid/doxorubicin (CuS@PDA–FA/DOX) for performing both photothermal and chemotherapeutic cancer treatment. The nanocomposite platform has ultrahigh loading levels (4.2 ± 0.2 mg mg−1) and a greater photothermal conversion efficiency (η = 42.7%) than CuS/PDA alone. The uptake of CuS@PDA–FA/DOX nanocomposites is much higher in MCF-7 cells than in A549 cells because MCF-7 cells have much higher folic acid receptors than A549. Under near infrared (NIR) irradiation, the CuS@PDA–FA/DOX system using a synergistic combination of photothermal therapy and chemotherapy yields a better therapeutic effect than either photothermal therapy or chemotherapy alone. The treatment is very effective with the cell viability is only 5.6 ± 1.4%. [ABSTRACT FROM AUTHOR]

A novel sensor array based on a (+)AuNP/AuNC nanocomposite was constructed for the selective discrimination of 10 types of Gram-negative bacteria (including 3 types of antibiotic-resistant strains) at a low concentration level of OD600 = 0.015. By recognizing the triple optical patterns of Gram-negative bacteria with the assistance of LDA, the sensor array is able to group the bacteria with respect to their species to each other. [ABSTRACT FROM AUTHOR]

Here we report a novel mechanism for triggering drug release in the polydopamine (PDA)-coated magnetic CuCo2S4 core–shell nanostructure by glutathione (GSH) triggered degradation of PDA for release. In the design, we used PDA coated CuCo2S4 as the nanocarrier with polyethylene glycol and folic acid targeting molecules to ensure the safe delivery of doxorubicin (DOX) to cancer cells. In addition, the controlled release could be enforced by taking advantage of the pH sensitivity of PDA to tumor acidic environments. The targeting and treatment of HeLa cancer cells were very effective and the killing was more efficient at higher levels of GSH. Furthermore, the designed system not only could be used for drug delivery but also could combine photothermal therapy with chemotherapy in a synergetic way. Plus, the system could be used for magnetic resonance imaging (MRI), which is beneficial for imaging-guided treatment. [ABSTRACT FROM AUTHOR]

Optical nanosensors capable of distinguishing D2O from H2O are rarely reported. Herein, we explore a scalable synthetic route for multicolor carbon polymer dots (CPDs) by utilizing Fe3+-catalyzed oxidative polymerization at as low as 80 °C. Notably, the CPDs exhibit differential optical responses to H2O and D2O. [ABSTRACT FROM AUTHOR]

Over the past few years, artificial enzymes have attracted enormous attention due to their high stabilities and cost-effective productions. In this work, metal–organic framework-derived SiW12@Co3O4 was synthesized in large quantities by stirring the mixture at ambient temperature and calcination. The obtained SiW12@Co3O4 exhibited a highly inherent peroxidase-like activity and excellent stability. Kinetic studies demonstrated that the synthesized SiW12@Co3O4 had a strong binding affinity to 3,3′,5,5′-tetramethylbenzidine (TMB), stronger than HRP had. Specifically, the peroxidase-like activity of SiW12@Co3O4 in an aqueous solution was well maintained after incubation at an elevated temperature, at an extreme pH and for a long time. A SiW12@Co3O4-based method was further developed for H2O2 and one-pot glucose detection with good sensitivity and reliability. The facile synthesis approach is expected to facilitate the practical use of metal–organic frameworks and their derivatives as enzyme mimics in the future. [ABSTRACT FROM AUTHOR]

A porous hybrid, namely PW12@TiO2–Si(Et)Si/Pba, is fabricated by the modification of PW12@TiO2–Si(Et)Si with pyridine boronic acid via a solvothermal method. The covalent interactions between the boronic acid group of the hybrid and the glycosylated site of proteins provide the as-prepared hybrid with favorable adsorption performance towards glycoproteins. The adsorption behaviors of glycoproteins onto the hybrid fit well with the Langmuir model, and the adsorption capacities for glycoprotein IgG and Trf are high, up to 348.5 mg g−1 and 262.6 mg g−1, respectively. Thus, a protocol for the depletion of high abundant glycoproteins from human plasma is proposed. The percentage contents of Trf, IgG, haptoglobinis and IgM are reduced from 7.38%, 5.5%, 3.01% and 1.02% to 0.951%, 4.7%, 0.126% and 0.76%, respectively. 85 low abundant proteins are identified from the raw plasma after the depletion of the high abundance proteins, demonstrating the potential of PW12@TiO2–Si(Et)Si/Pba hybrid in proteomic studies. [ABSTRACT FROM AUTHOR]

Tryptophan (Trp) modified aminated mesoporous silica nanoparticles (AMSNs), shortened to Trp-AMSNs, are prepared via covalent binding. The obtained Trp-AMSNs exhibit a uniform size of ca. 83 nm, a mesopore diameter of ca. 2.6 nm, along with a pore volume of 0.439 cm3 g−1. It is demonstrated that Trp-AMSNs selectively adsorb ovalbumin (Ova) from complex biological matrices. At pH 5.0, 1.0 mg of Trp-AMSNs produces an adsorption efficiency of 96% for 100 mg L−1 Ova in 1.0 mL of solution. An adsorption capacity of 1240.3 mg g−1 is derived for Ova, which is much improved with respect to that of the native AMSNs. The retained Ova could be readily recovered by a sodium dodecyl sulfate (SDS) solution (0.5%, m/v), providing a recovery of 71.2%. Trp-AMSNs are further applied for the isolation of Ova from a protein mixture (with a molar ratio of ovalbumin/lysozyme of 1 : 10) and an egg-white sample. High-purity Ova is obtained, as demonstrated by SDS-PAGE assay results. [ABSTRACT FROM AUTHOR]

The crosstalk between phosphoproteins and glycoproteins causes many difficulties in their selective isolation/enrichment from biological samples. This issue is of high significance in proteomics study, but thus far, it has not received proper attention. Herein, an arginine-functionalized polyhedral oligomeric silsesquioxane (POSS) framework, PP-x-Arg (x = 0, 1, 2, … denotes the amount of salt in preparation), was developed by combining salt-templated thermal polymerization of POSS and pyromellitic dianhydride (PMDA) with post-modification using arginine. PP-x-Arg possesses a porous nanostructure and abundant functional groups, namely, guanidine and zwitterionic groups, enabling the selective adsorption of phosphoproteins or glycoproteins via specific phosphate–guanidine affinity or hydrophilic interaction between PP-x-Arg and glycoproteins, respectively. In particular, the adsorption selectivity exhibited by PP-x-Arg can be easily regulated by adjusting the pH values of the adsorption medium. The PP-x-Arg framework was further employed for the discrimination and isolation of phosphoproteins and glycoproteins from biological samples. [ABSTRACT FROM AUTHOR]

A nonthermal optical emission spectrometric (OES) system is developed for the simultaneous multi-element determination of zinc, cadmium and mercury, with a dielectric barrier discharge (DBD) microplasma generated on the nozzle of a pneumatic micronebulizer as the excitation source. After solution nebulization, zinc, cadmium and mercury are directly atomized and excited in the spray by a DBD microplasma for performing optical emission. The emission spectra are measured with a charge-coupled device (CCD) spectrometer. Various important parameters governing the analytical performance of the nonthermal OES system are scrutinized, encompassing the conditions of sample solution introduction, microplasma formation, signal collection and matrix matching for DBD-OES detection. With the characteristic emission lines of Zn 213.9 nm, Cd 228.8 nm and Hg 253.7 nm as the analytical lines for quantification, the detection limits for the simultaneous determination of Zn, Cd and Hg are 22, 1.6, and 10 μg L−1, respectively, and the corresponding linear ranges are 70–6000, 5–1000, and 35–2000 μg L−1, respectively. The accuracy of the present nonthermal OES system is confirmed by the determination of Zn, Cd and Hg in two certified reference materials, i.e., CRM 176 (city waste incineration ash) and GBW 08608 (water). The proposed nonthermal OES system provides a portable instrument for field analysis in emergency with low cost and low consumption. [ABSTRACT FROM AUTHOR]

Microplasmas have become an actual topic of interest for research in atomic spectrometric systems. Their excellent characteristics including low power consumption and small size and weight make the use of microplasmas a promising technique for developing portable analytical instrumentations for the real-time and on-site measurement of trace species. In this review, the current status of discharge-based microplasmas is presented and discussed from the viewpoint of four typical applications in the field of atomic spectrometry, i.e., excitation source, atomizer, ionization source, and induced vapor generation. Microplasma excitation sources are not only highlighted for the direct detection of trace species by optical emission spectrometry (OES), but also focused on for a series of coupling techniques with gas chromatograph (GC), microelectrodialysis (μED), capillary electrophoresis (CE), chemical vapor generation (CVG), and electrothermal vaporization (ETV). Besides the atomization function, microplasma atomizers could serve as a preconcentration device to achieve the trapping and release of analytes in atomizers. Microplasma ionization sources are used to ablate compounds from sample surfaces for analyte detection and profile analysis. Microplasma-induced vapor generation provides a novel sample introduction approach with the feature of being a green analytical method. The future prospects of microplasma application in the field of atomic spectrometry are also described. [ABSTRACT FROM AUTHOR]

Mesoporous carbon nanomaterials have found applications in drug delivery and cancer therapy. However, it is still quite challenging to fabricate their multifunctional counterparts with high selectivity and efficiency for cancer theranostics. In this study, an alternative and multifunctional nanoplatform was developed, wherein mesoporous carbon nanoparticles (MCNs) were first encapsulated with a polyacrylic acid (PAA) shell, and after doxorubicin (DOX) loading, a polyethyleneimine (PEI) layer was coated to prevent the leakage of DOX. The MUC1 aptamer (Apt) was subsequently anchored onto the surface to provide the ability for specific recognition of cancer cells. This nanocarrier has been shortly termed as Apt@DP-DOX-MCN. The double polymer shells endowed the drug carrier platform with glutathione (GSH) and pH dual stimuli-responsive capability, and controllable release of the encapsulated drug molecule could be realized from the mesoporous and hollow structure, providing a 60% release of the loaded drug. Considering that most tumor sites exhibit more acidic environments or high redox potential, the pH- and GSH-sensitive release capability is particularly useful for controlled drug delivery in cancer therapy as it takes advantage of the inherent characteristics of tumor cells. The anchored MUC1 aptamer facilitates spatiotemporal therapy to improve selectivity towards the objective lesion site and decrease the off-target toxicity. Moreover, the targeted recognition and therapy of human lung adenocarcinoma cancer cells (A549) and breast cancer cells (MCF-7) was successfully achieved. [ABSTRACT FROM AUTHOR]

An automated microelectrodialysis (μED)-liquid electrode discharge (LED)-optical emission spectrometric (OES) system was developed with the aim of potassium screening in serum, especially for a micro-sample volume. Potassium in serum was on-line extracted via a μED process and subsequently introduced into the LED microplasma to perform the optical emission detection at λem 766.5 nm. The optical emission intensity of potassium was measured using a charge-coupled device (CCD) spectrometer for quantitative analysis. A few important parameters governing the extraction of potassium by μED and its detection by LED-OES were investigated. The present system provides an excellent capability for eliminating matrix interference with a protein removal efficiency of ＞99%, by consuming a serum sample volume of 20 μL for each analysis. The entire analytical process, including sample introduction, pretreatment and detection, takes no more than 90 s. A detection limit of 0.6 mg L−1 was obtained along with a linear range of 2–70 mg L−1 and a RSD value of 4.8% at 5 mg L−1 potassium. The practical applicability of the μED-LED-OES system was demonstrated by the determination of potassium in serum certified reference materials and real human serum samples. The present system offers a potential strategy for screening the variation of the concentration of potassium in patients. [ABSTRACT FROM AUTHOR]

A facile and green approach for the preparation of a multifunctional ternary Fe2O3/graphitic-C3N4/graphene (FeCNG) nanocomposite with a porous structure is reported. This entails the growth of Prussian blue (PB) and adsorption of urea on graphene oxide (GO), followed by thermal pyrolysis of PB and urea leading to in situ formation of a porous N-doped graphene/iron oxide architecture. This strategy for the generation of FeCNG requires no structure-directing surfactants and gives rise to an N-doped composite capable of separation for recycling. The FeCNG architecture is capable of both rapid reduction of p-nitrophenol (4-NP) and efficient scavenging of Cr(vi) in aqueous media. The reduction of 4-NP to p-aminophenol by NaBH4 could be achieved within 3 min at 25 °C, using catalyst loadings as low as 1 mg. Cr(vi) adsorption was evaluated by Langmuir and pseudo-second-order models, offering a maximum equilibrium adsorption capacity of 149 mg g−1. In particular, Cr(vi) could be effectively adsorbed by the FeCNG nanocomposite and thereby reduced to less toxic Cr(iii). By virtue of the enhanced catalytic performance and highly efficient adsorption of Cr(vi) across a wide pH range, the FeCNG nanocomposite possesses a broad application potential in energy and environmental sciences. [ABSTRACT FROM AUTHOR]

A novel polyoxometalate (POM)-based hybrid is prepared for the selective adsorption of acidic and/or basic proteins. The solidification of the POM moiety P8W48 is firstly achieved through dehydration condensation between the –OH group on the P8W48 surface and the Si–OH of aminopropyltriethoxysilane (APTS), and thereafter further condensation of the P8W48O184–APTS intermediate with poly(acrylic acid) (PAA) produces a hybrid, by linking carboxyl groups in PAA with –NH2 groups in P8W48O184–APTS via the formation of an amide bond. The P8W48–APTS–PAA hybrid surface is negatively charged due to abundant COO− groups from PAA, which provides electrostatic interactions with positively charged proteins by varying pHs. Meanwhile, the d–p π bond in P8W48 offers strong affinity to other proteins viaπ–π stacking interaction. The hybrid thus offers potential for achieving selective adsorption of either acidic or basic proteins by simply controlling the adsorption conditions, i.e., pH value or ionic strength of the adsorption medium. With ovalbumin (Ova) and lysozyme (Lys) as the models of acidic and basic proteins, their adsorption behaviors fit the Langmuir model, with adsorption capacities of 367.0 mg g−1 and 74.0 mg g−1, respectively. The retained proteins are readily recovered with 0.01 mol L−1 CTAB, providing recoveries of 89.0% for Ova and 93.0% for Lys. The P8W48–APTS–PAA hybrid is further applied for the isolation of Ova and Lys from real biological samples, egg white. [ABSTRACT FROM AUTHOR]