Oriented-aptamer encoded magnetic nanosensor with laser-induced fluorescence for ultrasensitive test of okadaic acid.

Okadaic acid (OA) biotoxin acts a well-established inhibitor of protein phosphatase even a tumor promoter of human being, arouse great attention in safety monitoring. However, the powerful and convenient nanosensing technologies for addressing the demands such as rapidity, high sensitivity, and stability in the in-field test of OA shellfish toxin is still scarce. Herein, a high-performance magnetic biometric nanosensor (MBNS) integrating oriented aptamers and ultrasensitive laser-induced fluorescence (LIF) was firstly proposed for the in-field detection of trace OA in seafoods.

Specific recognition and determination of trace phthalic acid esters by molecularly imprinted polymer based on metal organic framework.

A novel hybrid material (ZIF-7-NH@MIP) combining high adsorption capacity of amino-functional zeolitic imidazolate framework and specific recognition ability of dual-template molecular imprinted polymer was synthesized. The prepared ZIF-7-NH@MIP was characterized by a range of instrumental techniques and combined with high performance liquid chromatography for the detection of four phthalate esters. The limits of detection of the four PAEs were below the maximum residue limit of GB 3838-2002 in China, ranging from 0.

Efficient and selective solid-phase microextraction of polychlorinated biphenyls by using a three-dimensional covalent organic framework as functional coating.

Developing functional fiber coating for selective solid phase microextraction (SPME) of trace pollutants is critical in environmental analysis. Herein, the novel covalent organic frameworks (COFs) with three-dimensional (3D) frameworks and multiple interactions were designed and presented for the selective SPME of polychlorinated biphenyls (PCBs). Using tetra (p-aminophenyl) methane (TAM) and 1,3,5-triformylphloroglucinol (Tp) as the monomers, the 3D TpTAM-COF was synthesized and possessed a large specific surface area, high thermal stability, and spatial selectivity toward PCBs.

Facile DNA adsorption enabling ammonium-based hydrophilic affinity monolithic column for high-performance online selective microextraction of ochratoxin A.

Herein, a facile protocol of simple DNA adsorption on UV-initiated polymerization supports was proposed for effectively fabricating aptamer-based affinity monolithic column. Hydrophilic cationic monolith with an excellent mechanical stability was achieved within 7 min and then massive aptamers were directly bound by DNA charge-dependent adsorption. Strong cationic quaternary ammonium-based monomer was employed to provide effective and stable positive charge surface for aptamer immobilization in a wide range of pH.

Aptamer-functionalized metal-organic framework-coated nanofibers with multi-affinity sites for highly sensitive, selective recognition of ultra-trace microcystin-LR.

A novel aptamer-functionalized metal-organic framework nanofibrous composite (viz. PAN/UiO@UiO2-N-aptamer) with a high aptamer coverage density was proposed based on the electrospinning and seeded growth method, and used for specific affinity recognition of trace Microcystin-LR (MC-LR). Heterobifunctional ligand was used to modify the metal-organic framework nanoparticles (MOF NPs) surface, which could passivate the MOF surface with respect to unmodified DNA, followed by coupling massive aptamers on MOF of the solid-phase microextraction (SPME) fiber using click chemistry.

Aptamer-functionalized metal-organic framework-based electrospun nanofibrous composite coating fiber for specific recognition of ultratrace microcystin in water.

A novel aptamer@AuNPs@UiO-66-NH electrospun nanofibrous coating fiber for specific recognition of microcystin-LR (MC-LR) was proposed by using electrospinning, metal-organic frameworks (MOF) seed growth and AuNPs bridging aptamer strategies. Characterization of morphology, structure and stability of the obtained affinity nanofibrous coating fiber were investigated. High loading of MOFs and aptamers on the nanofibrous fiber were achieved and successfully applied for accurate identification of MC-LR by solid-phase microextraction (SPME) coupled with LC-MS.

In situ photo-initiated polymerized oligonucleotide-functionalized hydrophilic capillary affinity monolith for highly selective in-tube microextraction of ochratoxin A mycotoxin.

A photo-initiated polymerized oligonucleotide-grafted hydrophilic affinity monolithic column was synthesized in situ, and exploited for selective in-tube solid phase micro-extraction (IT-SPME) protocol towards the sensitive detection of ochratoxin A (OTA). Only 7 min was required for the rapid polymerization of aptamer-based affinity monolith, which was much less than the reaction time of most thermal polymerization (12-16 h) and sol-gel chemistry methods (up to 52 h). Characterizations such as polymerization recipes, structure morphology, FTIR spectrum, elemental mapping, mechanical stability, and specific recognition performance were evaluated.

A facile aptamer immobilization strategy to fabricate a robust affinity monolith for highly specific in-tube solid-phase microextraction.

Developing a functional affinity monolithic column towards in-tube solid-phase microextraction (IT-SPME) for selective sample pretreatment is critical. Herein, a high-performance capillary affinity monolithic column with an ultra-high aptamer coverage density was rapidly fabricated a simple adsorption strategy, in which aptamers with natural sequences were directly immobilized on an ammonium-based strongly cationic matrix. Limitations of the traditional biological or covalent methods such as time-consuming modification reactions, special requirement of active groups ( -NH and -SH) on the aptamer, and low aptamer coverage density levels were avoided.

Static Retention of Dynamic Chiral Arrangements for Achiral Shear Thinning Metal-Organic Colloids.

Chiral compounds are known to be important not only because they are the fundamental components of living organisms, but also for their unique chiroptical properties. In recent years, scientists have fabricated several chiral organic supramolecular aggregates by using chiral physical fields, such as vortex flow. Herein, the relationship between dynamic chiroptical properties and rheological nature is discussed, suggesting the shear thinning properties of non-Newtonian fluids might help colloidal particles adopt a chiral arrangement in vortices.

Towards highly specific aptamer-affinity monolithic column by efficient UV light-initiated polymerization in "one-pot".

Time-consuming or tedious operation in multiple-step process might is the obstacle for efficiently preparing aptamer-affinity monolithic column. Here, a new and facile strategy to prepare aptamer-based hybrid affinity monolith in "one-pot" at room temperature was exploited, in which UV light-initiated free-radical polymerization and "thiol-ene" click reaction were implemented simultaneously. Only 7 min was cost for finishing the polymerization reaction, which was only 1/100 of that for the traditional thermal polymerization.

Heteroporous 3D covalent organic framework-based magnetic nanospheres for sensitive detection of bisphenol A.

Covalent organic frameworks (COFs) showed great promise in effective adsorption of target molecule via size selectivity. Although various magnetic 2D COFs composites have been studied and exhibited the intensive applications, the incorporation of 3D COFs and magnetic nanoparticles to form a new class of magnetic adsorbents with enhanced function still has no reports. Herein, a novel FeO@3D COF with heteroporous structure matching to the sizes of bisphenol A (BPA) was firstly synthesized for better adsorption of BPA than common magnetic 2D-COFs.

Circularly Polarized Luminescence of Achiral Metal-Organic Colloids and Guest Molecules in a Vortex Field.

Recently, scientists have reported a range of chiral fluorescence materials or chiral composites that can emit circularly polarized luminescence. Herein, two achiral metal-organic colloidal solutions were studied, showing active circularly polarized luminescence, which is observed in vortex stirring. The absolute values for g are 0.

A novel adsorbent based on aptamer prepared via "thiol-ene" click for specific recognition of phthalic acid esters.

In this paper, a novel adsorbent based on aptamer was prepared via "thiol-ene" click chemistry reaction and used for selective adsorbing the trace phthalic acid esters (PAEs) from drinking water and juice samples, which depended on the group selectivity of aptamers to the ester and the benzoyl groups of PAEs. The morphological structures of the obtained adsorbents were characterized by Fourier Transform infrared spectroscopy (FT-IR), fluorescence spectra, Energy Dispersive Spectrometer (EDS), Brunauer-Emmett-Teller (BET). The selectivity of the prepared adsorbent was evaluated and the results showed that the recovery of the adsorbent with aptamer for PAEs was 66.

Towards online specific recognition and sensitive analysis of bisphenol A by using AuNPs@aptamer hybrid-silica affinity monolithic column with LC-MS.

Highly specific sample pretreatment for the sensitive detection of trace bisphenol A (BPA) in compliacted samples is critical. Herein, a new protocol towards online specific recognition and sensitive detection of BPA was proposed by using Aptamer@AuNPs-modified affinity monolith coupled with LC-MS. Optimization of polymerization conditions and characterization such as the morphology, energy spectrum, mechanical stability, aptamer coverage density and specific performance of the affinity monolith were studied.

Online high-efficient specific detection of zearalenone in rice by using high-loading aptamer affinity hydrophilic monolithic column coupled with HPLC.

Via the facile photopolymerization and thiol-ene click chemistry, a hydrophilic polyhedral oligomeric silsesquioxane (POSS)-containing affinity monolithic column with a high load of aptamers and fast preparation was presented, and successfully applied to the efficient specific recognition and sensitive detection of zearalenone (ZEN) by coupling with HPLC. Optimization of polymerization reaction and polymer recipe were studied, and characteristics such as structural morphology, affinity performance and specificity to ZEN were evaluated. A highly hydrophilic POSS-based aptamer affinity monolith was rapidly prepared in 1.

Towards high-efficient online specific discrimination of zearalenone by using gold nanoparticles@aptamer-based affinity monolithic column.

Sensitive and specific analysis of zearalenone (ZEN) mycotoxin in cereals for ensuring food safety is critical and remains challenging. Herein, a new gold nanoparticles @aptamer-functionalized hybrid affinity monolithic column was proposed and employed for online specific recognition of ZEN by HPLC. Characterization on the morphology, Brunauer-Emmett-Teller (BET) surface area mechanical stability and specific performance of the obtained affinity monolith were investigated.

Facile preparation of stainless steel microextraction fiber via in situ growth of metal-organic framework UiO-66 and its application to sensitive analysis of polycyclic musks.

A functional stainless steel microextraction fiber easily prepared by in situ growing metal-organic framework UiO-66 was presented and used for high-performance analysis of polycyclic musks. Via the robust Ag-SH bonding reaction, mercaptoacetic acid was easily anchored on Ag film to provide carboxyl group on the stainless steel fiber, then in situ grown UiO-66 was fulfilled via the coordination reaction between Zr and carboxyl group. Good characteristics including large surface area, high thermal stability, and good adsorption property were achieved.

A double-recognized aptamer-molecularly imprinted monolithic column for high-specificity recognition of ochratoxin A.

In this study, a double-recognized aptamer-molecularly imprinted monolithic column (Apt-MIP monolithic column) was prepared by introducing both aptamer and MIP to reduce non-specific adsorption. Its preparation parameters such as the time of photo-initiation, the dosage of photo-initiator and the concentration of aptamer were investigated in detail. The recovery ratios of ochratoxin A (OTA) to ochratoxin B (OTB) on Apt-MIP monolithic column, Apt monolithic column and MIP monolithic column were 116.

Highly efficient preparation of β-CD-based chiral monolithic column by "one-pot" hydroxymethyl polycondensation for enantioseparation in capillary liquid chromatography.

A facile strategy for highly efficient fabrication of chiral monolithic column was carried out by the simple "one-pot" hydroxymethyl polycondensation of native β-cyclodextrin (β-CD) and urea-formaldehyde (UF). In-situ rapid substitution of native β-CD and efficient polycondensation of β-CD products and UF oligomers was proposed and fulfilled in one pot. The feasibility, mechanism and key parameters of polycondensation reaction were discussed.

Amphiphilic gemini-iridium (III) complex for rapid and selective detection of picric acid in water and intracellular.

Inspired by the structure and properties of gemini surfactant, a novel amphiphilic gemini-iridium complex (GIC-Ir) has been developed, which can spontaneously form vesicles by self-assembly and exhibit excellent dispersibility and high emission intensity in water. The emission of GIC-Ir can be rapidly and selectively quenched by picric acid (PA) due to the aromatic groups and two long-chain quaternary ammonium (QA) groups with positive charge, which endow GIC-Ir vesicles outstanding capability to capture negatively charged PA, and greatly promote the interaction between GIC-Ir and PA. Theoretical calculations and spectral studied indicated that the photoinduced electron transfer and resonance energy transfer may be responsible to the emission quenching.

Preparation of aptamer-bound polyamine affinity monolithic column via a facile triazine-bridged strategy and application to on-column specific discrimination of ochratoxin A.

Developing a high-performance modification protocol is critical for efficiently fabricating affinity monolith. Herein, by using 2,4,6-trichloro-1,3,5-triazine as the linker, a simple triazine-bridged approach was proposed for efficiently fabricating aptamer-grafted polyhedral oligomeric silsesquioxane-polyethyleneimine affinity monolith with high specificity toward ochratoxin A. Experimental parameters, column characteristics and specificity performances of the resultant affinity monolith were investigated in detail.

Preparation and evaluation of highly hydrophilic aptamer-based hybrid affinity monolith for on-column specific discrimination of ochratoxin A.

Nonspecific adsorption is a challenge of specific recognition on aptamer-based affinity monoliths. Here, a novel highly hydrophilic polyhedral oligomeric silsesquioxane (POSS)-containing aptamer-based hybrid-silica affinity monolith with a good recognition nature was prepared and used for specific discrimination of ochratoxin A (OTA). A homogeneous polymerization mixture consisted of POSS chemicals, hydrophilic monomers and aptamer solution was directly polymerized via the "one-pot" method.

Amphiphilic Gemini Iridium(III) Complex as a Mitochondria-Targeted Theranostic Agent for Tumor Imaging and Photodynamic Therapy.

Clinical diagnostics and therapeutics of tumors are significantly benefitted by the development of multifunctional theranostic agents, which integrate tumor targeting, imaging, and therapeutics. However, the integration of imaging and therapy functionalities to a unimolecular framework remains a great challenge. Herein, a family of amphiphilic gemini iridium(III) complexes (GIC), Ir1-Ir6, are synthesized and characterized.

Sensitive amperometric detection for capillary electrophoresis of phenol carbamates with in-line thermal hydrolysis strategy.

A strategy on amperometric detection for CZE of phenol carbamates as model analytes with a facile in-line thermal hydrolysis was presented, in which a thermal hydrolysis, subsequent CZE separation and final column-end amperometric detection were accomplished in an intact capillary. Key parameters of hydrolysis dynamics of carbamates and electrochemical detection of the hydrolysates were studied, as well as electrophoretic conditions. Under the optimal conditions, the capillary was utilized as chambers for in situ hydrolysis, CZE separation, and electrochemical detection.

Highly hydrophilic polyhedral oligomeric silsesquioxane (POSS)-containing aptamer-modified affinity hybrid monolith for efficient on-column discrimination with low nonspecific adsorption.

A novel polyhedral oligomeric silsesquioxane (POSS)-containing aptamer-modified hybrid affinity monolith with excellent hydrophilicity and unique architecture without Si-OH groups is presented herein, and the nonspecific adsorption caused by the hydrophobic nature of the monolithic column or polar interaction with silanol groups is minimized. Via a simple "one-pot" procedure, hydrophilic monomers were facilely polymerized with the POSS-methacryl substituted (POSS-MA) and aptamer; a highly hydrophilic nature was obtained and the lowest contact angle of 11° was achieved. By using ochratoxin A (OTA) as the model analyte, highly selective recognition of OTA in the mixture was achieved and the control of nonspecific interactions and the cross-reactivity of OTB and AFB1 were significantly improved.