Metal-free visible-induced C(sp)-C(sp) coupling of quinoxalin-2()-ones oxidative cleavage of the C-N bond.

A C(sp)-C(sp) reaction between aromatic hydrazines and quinoxalines has been developed through a photocatalytic system. The protocol is established for C(sp)-N bond cleavage and direct C(sp)-H functionalization for the coupling of C(sp)-C(sp) photocatalysis under mild and ideal air conditions without the presence of a strong base and metal. The mechanistic studies reveal that the generation of a benzene radical the oxidative cleavage of aromatic hydrazines for the cross-coupling of C(sp)-C(sp) with the assistance of a photocatalyst is essential.

Controllable release ratiometric fluorescent sensor for hyaluronidase via the combination of Cu-Fe-N-C nanozymes and degradable intelligent hydrogel.

As a popular controllable-released carrier, intelligent hydrogels are often used in drug delivery and disease therapeutics. Meanwhile, benefit from the mimic-enzyme activity performance, Fe-N-C nanozymes have been widely used in sensing and analysis. However, the combination of intelligent hydrogels with specific degradability and Fe-N-C nanozymes with enhanced activity in one system to achieve controllable and sensitive detection is rare.

A dual-mode strategy for sensing and bio-imaging of endogenous alkaline phosphatase based on the combination of photoinduced electron transfer and hyperchromic effect.

Benefit from the additional correction of the output signal in dual-mode detection, traditional dual signal readout strategies are performed by constructing the ratiometric fluorescent probe through excitation energy transfer (EET) or fluorescence resonance energy transfer (FRET). To avoid the complicated modification process and obtain the results rapidly, a simple dual-mode sensing strategy based on the electronic effects of p-nitrophenol (PNP) is described to monitor the activities of alkaline phosphatase (ALP). In the sensing platform, p-nitrophenylphosphate was used as a substrate to produce the PNP using ALP as the catalyst.

A fluorescence signal amplification and specific energy transfer strategy for sensitive detection of β-galactosidase based on the effects of AIE and host-guest recognition.

Benefit from the efficient energy transfer, aggregation-induced emission (AIE) and host-guest recognition as strategies of signal amplification and specific binding have been applied to establish the sensing system; however, the application of these two attractive strategies in one system is rare. Herein, we propose a "turn-on" to "turn-off" fluorescent strategy for sensitive detection of β-galactosidase (β-Gal) based on the application of AIE and host-guest recognition. In this work, a novel red-emitted (635 nm) copper nanoclusters (CuNCs) protected by dithioerythritol (DTE) and β-cyclodextrin (β-CD) has been found to possess AIE property induced by aluminum cations to achieve the "turn-on" process, and the coordinated behavior between aluminum cations and DTE/β-CD CuNCs is also discussed.