Simultaneous detection of CaMV35S and NOS using fluorescence sensors with dual-emission silver nanoclusters and catalytic hairpin amplification strategy.

A dual-emission fluorescent biosensing method was developed for simultaneous determination of CaMV35S and NOS in genetically modified (GM) plants. Two designed hairpin DNA (H1, H2) sequences were used as templates to synthesize H1-AgNCs (λ = 570 nm, λ = 625 nm) and H2-AgNCs (λ = 470 nm, λ = 555 nm). By using H1-AgNCs and H2-AgNCs as dual-signal tags, combined with signal amplification strategy of magnetic separation to reduce background signal and an enzyme-free catalytic hairpin assembly (CHA) signal amplification strategy, a novel multi-target fluorescent biosensor was fabricated to detect multiple targets based on FRET between signal tags (donors) and magnetic FeO modified graphene oxide (FeO@GO, acceptors).

Dinuclear Zinc-Catalyzed Asymmetric Desymmetrization of Cyclopentendiones: Access to Functional Cyclopentanediones Bearing an All-carbon Quaternary Stereocenter.

The success in the identification of the two enantioisomeric surfaces of electrophiles by dinuclear zinc catalysts is disclosed. This protocol realizes a dinuclear zinc-cocatalyzed desymmetrization of cyclopentendiones using α-hydroxy aryl ketones as nucleophiles through Michael addition reaction. Under mild conditions, a series of functional cyclopentanediones bearing multiple stereogenic centers including an all-carbon quaternary stereocenter, were obtained in moderate to good yields with excellent stereoselectivities.