An epoxide-based covalent sensor to detect cardiac proteome aggregation in a cardio-oncology model.

Covalent sensors to detect and capture aggregated proteome in stressed cells are rare. Herein, we construct a series of covalent fluorogenic sensors for aggregated proteins by structurally modulating GFP chromophore and arming it with an epoxide warhead. Among them, P2 probe selectively modifies aggregated proteins over folded ones and turns on fluorescence as evidenced by biochemical and mass spectrometry results. The coverage of this epoxide-based covalent chemistry is demonstrated using different types of aggregated proteins. Finally, the covalent fluorescent sensor P2 allows for direct visualization and capture of aggregated proteome in stressed cardiomyocytes and cardiac tissue samples from a cardio-oncology mouse model. The epoxide-based covalent sensor developed herein may become useful for future chemical proteomics analysis of aggregated proteins to dissect the mechanism underlying cardio-oncology.

Frogspawn inspired hollow Fe3C@N-C as an efficient sulfur host for high-rate lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries with high theoretical energy densities of ∼2600 W h kg-1 have been recognized as a promising energy storage device. However, the practical application of Li-S batteries is still limited by the cycle stability and rate capability, which is highly relied on the well-designed cathode material. Inspired by the unique structure of frogspawn in Nature, a hollow Fe3C@N-C with frogspawn-like architecture was successfully constructed as a highly efficient sulfur host in this paper. Derived from a Prussian blue self-template, Fe3C@N-C possesses a metal-like Fe3C spawn core and the high conductivity of an N-doped carbon shell. This unique structure enables a large surface area, fast e-/Li+ transport, as well as a large hollow space for the volumetric expansion of the sulfur cathode. Moreover, with the N-doped carbon shell and the polar Fe3C core, the trapping and catalytic conversion of intermediate polysulfides are also facilitated. The strongly coupled interaction of polar Fe3C and polysulfides is confirmed by both theoretical calculations and electrochemical performance. Specifically, the Fe3C@N-C/S electrode presents a high capacity of 1351 mA h g-1 at 0.1C with the Fe3C@N-C as an integrated sulfur host. In particular, the rate capability and cycling stability of the Fe3C@N-C/S electrode is outstanding. It displays a high capacity of 792 mA h g-1 at 5C and a low capacity decay rate of 0.08% per cycle at 0.5C after 400 cycles. This work opens a convenient and economical avenue to design a frogspawn-like hollow metal carbide/carbon as an efficient sulfur host for advanced Li-S batteries.