Such metal induced quenching cannot be recovered by NaBH4. Electronic absorption and mass spectrometry studies offered further insights into the oxidation reaction. Our results correlate many important experimental observations and will fuel the further growth of this field.2

Abstract

ITC reveals the increasingly importance of entropy for heavier lanthanides binding to nucleotides. The phosphate group forming chelating effect with purine bases but not with pyrimidines.

It has been recently reported that the fluorescence of some DNA templated silver nanoclusters (AgNCs) can be significantly enhanced upon hybridizing with a partially complementary DNA containing a Grich overhang near the AgNCs. This discovery has found a number of analytical applications but many fundamental questions remain to be answered. In this work, the photostability of these activated AgNCs is reported. After adding the G-rich DNA activator, the fluorescence intensity peaks in ~1 h and then starts to decay, where the decaying rate is much faster with light exposure. The lost fluorescence is recovered by adding NaBH4, suggesting that the bleaching is an oxidative process.Once activated, the G-rich activator can be removed while the AgNCs still maintain most of their fluorescence intensity. UV-vis spectroscopy suggests that new AgNC species are generated upon hybridization with the activator. The base sequence and length of the template DNA have also been varied, leading to different emission colors and color change after hybridization. G-rich aptamers can also serve as activators. Our results indicate that activation of the fluorescence by G-rich DNA could be a convenient method for biosensor development since the unstable NaBH4 is not required for the activation step.

No abstract

2020 was a very special year for polymer science as the 100-year anniversary of its initiation by Staudinger. The past 100 years have been a prosperous time for polymer science, filled with discovery and innovation. Since plastics are lightweight, mechanically robust, and cheap, their use has proliferated, becoming pervasive in all sectors of society and ushering in the so-called heyday of plastics. At the same time, however, the plastics and rubbers developed by polymer science have caused catastrophic damage to the environment as long-lasting wastes continue to accumulate in the disposable age. Incinerating these materials generates carbon dioxide, which accelerates global warming while dumping them into the ocean results in their eventual disintegration into microplastics, small pieces that are consumed and accumulate in the food chain. As of 2015, only 9% of the 6300 million metric tons of plastics produced had been recycled,1 and unless far-reaching policies are adopted in the next decade to change the social structure that has so far been dependent on disposable polymers, global warming will continue to accelerate and it will certainly be difficult to pass on livable earth to future generations. Although this crisis is widely acknowledged, society has thus far been unable to give up such convenient and cheap materials. If we fail to shift our economic priorities or invent new materials as alternatives, it will be impossible to escape from this plastic world.

Herein, we report an ATP‐responsive nanoparticle (GroELNP) whose surface is fully covered with the biomolecular machine “chaperonin protein GroEL”. GroELNP was synthesized by DNA hybridization between a gold NP with DNA strands on its surface and GroEL carrying complementary DNA strands at its apical domains. The unique structure of GroELNP was visualized by transmission electron microscopy including under cryogenic conditions. The immobilized GroEL units retain their machine‐like function and enable GroELNP to capture denatured green fluorescent protein and release it in response to ATP. Interestingly, the ATPase activity of GroELNP per GroEL was 4.8 and 4.0 times greater than those of precursor cysGroEL and its DNA‐functionalized analogue, respectively. Finally, we confirmed that GroELNP could be iteratively extended to double‐layered (GroEL)2 ${{^{({\rm GroEL}){_{2}}}}}$ NP.

Herein, we report an ATP-responsive nanoparticle ( GroEL NP) whose surface is fully covered with the biomolecular machine "chaperonin protein GroEL". GroEL NP was synthesized by DNA hybridization between a gold NP with DNA strands on its surface and GroEL carrying complementary DNA strands at its apical domains. The unique structure of GroEL NP was visualized Angewandte Chemie