Synthesis of 2-imidazoles copper-catalyzed homo/cross-coupling of oxime acetates.

A facile and practical protocol to construct 2-imidazoles by applying an oxime acetate block as the sole component oxidative homo/cross-coupling catalyzed by Cu(I) was developed. This strategy provides a straightforward method to produce a series of substituted 2-imidazoles in moderate to excellent yields. The transformation process is straightforward to operate and is considered as a readily available catalytic system exhibiting good substrate compatibility, eliminating the necessity for pre-functionalization of azides or the use of additives.

A novel "mix-response" biosensor for colorimetric and photothermal dual-mode detection of sulfide ions in food based on silver-doping Prussian blue nanoparticle.

Effective identification of sulfur ions (S) in foodstuff is crucial for food safety and human health, but it remains challenging. Traditional single-mode colorimetric sensing methods are simple and sensitive, but are prone to interference from colored substances which can lead to false positives or negatives results. Herein, we develop a novel "mix-response" biosensor for colorimetric and photothermal dual-mode detection of S with good simplicity, sensitivity and portability.

A dual-mode ratiometric probe using europium-doped cyclen-functional carbon dots for fluorescent and point-of-care detection of tetracycline.

The overuse of tetracycline (TC) has led to the accumulation of antibiotic residues in drinking water and animal products, which can consequently lead to bacteria resistance and chronic disease in humans. Urgently addressing the need for a rapid, user-friendly, and point-of-care test for TC detection. In this work, we use cyclen and citric acid to synthesise carbon dots (CDs) with a unique ring-shaped structure on their surface and combine them with europium (Eu) to form an Eu-CDs fluorescent probe.

Photodriven Radical Perfluoroalkylation-Thiolation of Unactivated Alkenes Enabled by Electron Donor-Acceptor Complex.

A clean and direct three-component radical 1,2-difunctionalization of various alkenes with perfluoroalkyl iodides and thiosulfonates enabled by the electron donor-acceptor complex has been developed under light illumination at room temperature. The approach offers a convenient and environmentally friendly route for the simultaneous incorporation of Csp-R and Csp-S bonds, affording valuable polyfunctionalized alkane derivatives containing fluorine and sulfur in satisfactory yields. Consequently, this methodology holds significant value and practicality in the field of organic synthesis.

Metal-free synthesis of 1,3-dichloro-1,5-diarylpentan-5-ones cascade oxidative radical addition of styrenes with CHCl.

A novel and efficient metal-free cascade oxidative radical addition of styrenes is developed for the construction of 1,3-dichloro-1,5-diarylpentan-5-ones. This protocol presents a practical one-pot procedure that delivers highly functionalized 1,3-dichloro-1,5-diarylpentan-5-ones in moderate-to-good yields with a broad substrate scope under mild conditions.

Refinery wastewater treatment via a multistage enhanced biochemical process.

Petroleum refinery wastewater (PRWW) that contains recalcitrant components as the major portion of constituents is difficult to treat by conventional biological processes. An effective and economical biological treatment process was established to treat industrial PRWW with an influent COD of over 2500 mg L in this research. This process is mainly composed of internal circulation biological aerated filter (ICBAF), hydrolysis acidfication (HA), two anaerobic-aerobic (A/O) units, a membrane biological reactor (MBR), and ozone-activated carbon (O-AC) units.

Weak coordinated nitrogen functionality enabled regioselective C-H alkynylation Pd(II)/mono--protected amino acid catalysis.

The exploration of weak coordinated amine derivative enabled regioselective C-H functionalization remains challenging due to the elusive achievement of reactivity and selectivity simultaneously. Herein, regioselective C-H alkynylation of various readily transformable nitrogen functionalities was developed with great efficiency, with the assistance of the mono-N-protected amino acid (MPAA) ligand via Pd(ii) catalysis proceeding via 5, 6 and 7-membered palladacycle intermediates.

The palladium-catalyzed direct C3-cyanation of indoles using acetonitrile as the cyanide source.

The ligand-free palladium-catalyzed C3-cyanation of indoles via direct C-H functionalization was achieved. This protocol, utilizing CHCN as a green and readily available cyanide source, produced the desired products in moderate to good yields through transition-metal-catalyzed C-CN bond cleavage.

Lipid-oligonucleotide conjugates for bioapplications.

Lipid-oligonucleotide conjugates (LONs) are powerful molecular-engineering materials for various applications ranging from biosensors to biomedicine. Their unique amphiphilic structures enable the self-assembly and the conveyance of information with high fidelity. In particular, LONs present remarkable potential in measuring cellular mechanical forces and monitoring cell behaviors.

A study on the treatment efficiency of internal circulation biological aerated filters for refinery wastewater and the transformation of main organic pollutants.

In this study, an internal circulation biological aerated filter (ICBAF) reactor was applied to pretreat refinery wastewater containing large amounts of organic pollutants. According to the composition change of inlet-and-outlet water, the main organic pollutants, including micromolecular organic-acids, aldehydes, ketones, phenols, and so forth, degraded well in ICBAF unit. The concentration of organic acids, alcohols, and esters changed from 648 to 90 mg/L, 130 to 90 mg/L, and 158 to 228 mg/L, respectively.

Analysis of glycan expression on cell surfaces by using a glassy carbon electrode modified with MnO nanosheets and DNA-generated electrochemical current.

Electrochemical assay for analysis of cell surface glycan expression is reported. Mannose on human breast cancer cells (type MCF-7) is selected as the glycan model. Gold nanoparticles are modified with binding aptamer for MCF-7 cells and act as electrochemical probe.

Enhanced photocatalytic performance of magnetic multi-walled carbon nanotubes/cerium dioxide nanocomposite.

An easily separated photocatalyst, magnetic multi-walled carbon nanotubes/cerium dioxide (MMWCNTs-CeO) nanocomposite, has been successfully prepared by hydrothermal synthesis and subsequent loading of magnetic nanoparticles. The synthesized nanocomposite was characterized by scanning electron microscope, transmission electron microscopy, X-ray photoelectron spectroscopy, powder X-ray diffraction, and vibrating sample magnetometer. The characterization results indicated the successful synthesis of MMWCNTs-CeO nanocomposite.

Amperometric detection of microRNA based on DNA-controlled current of a molybdophosphate redox probe and amplification via hybridization chain reaction.

An electrochemical sensor is described for the determination of microRNA-21 by combing the DNA generated current with target-triggered hybridization chain reaction (HCR). A thiol-modified hairpin capture probe was first immobilized on a gold electrode. In the presence of microRNA-21, hybridization leads to a conformational change of the capture probe.

Synthesis and photophysical properties of europium(III)-β-diketonate complexes applied in LEDs.

Six β-diketonate ligands were used to prepare the corresponding antenna europium(III) ternary complexes using 1,10-phenanthroline as an ancillary ligand. All the complexes exhibited high decomposition temperatures. Photophysical properties such as FT-IR spectra, UV-Vis absorption spectra, excitation and emission spectra, relative luminescent intensity ratios, luminescence decay curves and quantum yields based on the complexes were systematically studied and compared with each other.

A universal amplified strategy for aptasensors: enhancing sensitivity through allostery-triggered enzymatic recycling amplification.

A universal amplified sensing strategy based on endonuclease was developed for designing fluorescence aptasensors. By employing hairpin-structured design for both recognition and reporter probes to decrease background signal, and a nicking endonuclease to perform target-triggered enzymatic recycling amplification, the proposed biosensor showed high sensitivity to target protein. To demonstrate the feasibility of the design, immunoglobulin E (IgE) was studied as a model target.

Label-free optical bifunctional oligonucleotide probe for homogeneous amplification detection of disease markers.

Oligonucleotide-based detection schemes that avoid chemical modification possess significant advantages, including simplified design, intrinsic affinity for targets, low cost and ease to extend applications. In this contribution, we developed a label-free self-locked bifunctional oligonucleotide probe (signaling probe) for the detection of different disease markers in parallel. Two signal enhancement techniques based on isothermal circular strand-displacement polymerization reaction, cyclical nucleic acid strand-displacement polymerization (CNDP) and cyclical common (nonnucleic acid) target-displacement polymerization (CCDP), were employed to implement the amplification assay for p53 gene and PDGF-BB, respectively.

High-sensitive electrochemical detection of point mutation based on polymerization-induced enzymatic amplification.

Here a highly sensitive electrochemical method is described for the detection of point mutation in DNA. Polymerization extension reaction is applied to specifically initiate enzymatic electrochemical amplification to improve the sensitivity and enhance the performance of point mutation detection. In this work, 5'-thiolated DNA probe sequences complementary to the wild target DNA are assembled on the gold electrode.

An aptazyme-based electrochemical biosensor for the detection of adenosine.

In this work, an aptazyme-based electrochemical biosensor for the detection of adenosine is reported. Aptazyme activity was modulated by appending an "inhibitor" oligonucleotide strand containing a 32-base adenosine aptamer to the 8-17 DNAzyme. In the absence of adenosine, the DNAzyme could not form appropriate catalytic structure due to the binding with the inhibitor strand.

A nano-porous CeO(2)/Chitosan composite film as the immobilization matrix for colorectal cancer DNA sequence-selective electrochemical biosensor.

CeO(2)/Chitosan (CHIT) composite matrix was firstly developed for the single-stranded DNA (ssDNA) probe immobilization and the fabrication of DNA biosensor related to the colorectal cancer gene. Such matrix combined the advantages of CeO(2) and chitosan, with good biocompatibility, nontoxicity and excellent electronic conductivity, showing the enhanced loading of ssDNA probe on the surface of electrode. The preparation method is quite simple and inexpensive.

Electrochemical detection of thrombin by sandwich approach using antibody and aptamer.

The goal of this work was to introduce a modified electrochemical sandwich model for target protein detection, exploiting antibody as the capturing probe, aptamer as the detection probe and methylene blue as the electrochemical active marker intercalating in the probing aptamer without previous labeling. With appropriate design of the sequence of the aptamer, the aptamer was successfully utilized instead of antibody for obtaining the electrochemical detection. A special immobilization interface consisting of nanogold-chitosan composite film was used to improve the conductivity and performance characteristics of the electrode.

Detection of adenosine using surface-enhanced Raman scattering based on structure-switching signaling aptamer.

In the present study, we report a novel sensitive method for the detection of adenosine using surface-enhanced Raman scattering (SERS) sensing platform based on a structure-switching aptamer. First, Ag-clad Au colloids film on a polished gold disc is prepared as enhanced substrate and modified with thiolated capture DNA. The formation of an aptamer/DNA duplex of expanded anti-adenosine aptamer and tetramethylrhodamine-labeled DNA (denoted TMR-DNA) is then developed, in which TMR-DNA could also hybridize completely with capture DNA.

Electrochemical immunosensor with aptamer-based enzymatic amplification.

An electrochemical immunosensor is reported by using aptamer-based enzymatic amplification with immunoglobulin E (IgE) as the model analyte. In this method, the IgE antibody is covalently immobilized as the capture probe on the gold electrode via a self-assembled monolayer of cysteamine. After the target is captured, the biotinylated anti-IgE aptamer is used as the detection probe.

QCM detection of DNA targets with single-base mutation based on DNA ligase reaction and biocatalyzed deposition amplification.

A novel biosensing technique for highly specific identification of gene with single-base mutation is proposed based on the implementation of the DNA ligase reaction and the biocatalyzed deposition of an insoluble product. The target gene mediated deposition of an insoluble precipitate is then transduced by quartz crystal microbalance (QCM) measurements. In this method, the DNA target hybridizes with a capture DNA probe tethered onto the gold electrode and then with a biotinylated allele-specific detection DNA.