Ambient-Light-Promoted Stereospecific Synthesis of (Z)-Vinyl Thioesters under Solvent- and Catalyst-Free Conditions.

An ambient-light-promoted stereospecific olefinic C(sp2)-S bond construction of thioacids and 1,1-diarylethenes has been demonstrated, affording various (Z)-vinyl thioesters in 51-85% yields under solvent- and catalyst-free conditions. Mechanistic studies indicated that the formation of thioacid-olefin complexes is responsible for generating a carbonyl thiyl radical and dioxygen in the air participates in the reaction and functions as a traceless reagent. Moreover, synthetic applications have been demonstrated by the gram scale synthesis and aggregation-induced emission property of representative compound 3i.

Indirect competitive-structured electrochemical immunosensor for tetrabromobisphenol A sensing using CTAB-MnO2 nanosheet hybrid as a label for signal amplification.

Tetrabromobisphenol A (TBBPA) is a kind of brominated flame retardant that is usually added to products to reduce their flame retardancy. However, its extensive use has resulted in their residues being found in the environment, which is very harmful. Herein, an indirect competitive immunosensor has been established for TBBPA detection based on the signal amplification system. Pd nanospheres in situ reduced on the surface of MnO2 nanosheet hybrid (MnO2/Pd) was used as the label for the secondary antibody through the Pd-N bond, and gold-toluidine blue composite was loaded onto MWCNTs (MWCNTs/Au-TB), which functioned as the platform for the immunosensor. The spherical structure of Pd had abundant catalytic active sites, which enhanced the catalytic activity of MnO2/Pd as the label, hence amplifying the signal response. Besides, MWCNTs/Au-TB improved electron transfer and produced a strong signaling pathway for immobilizing antigens through the Au-NH2 bond, which can specifically recognize primary antibodies to improve sensitivity. The immunosensor had a linear concentration range of 0-81 ng/mL, a low detection limit of 0.17 ng/mL (S/N = 3), with good stability, selectivity, and reproducibility based on the above advantages. Additionally, the acceptable accuracy and recoveries (recoveries, 92-124%; CV, 3.3-8.8%) in the real water sample analysis indicated that this strategy is promising for emerging pollutant analysis.