A novel multiply synergetic Si@rGO/g-C3N4 as an ultra-long-life anode material for lithium-ion batteries was synthesized successfully via stable interface bonding.

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A simple, rapid, label-free, and sensitive fluorescence strategy has been developed for screening the ligands binding to poly(dA) based on exonuclease I-assisted background noise reduction. In this strategy, we have designed 16-repeat deoxyribonucleic acids (A16) as a DNA probe and a double-stranded-chelating dye SYBR Green I (SG I) as a fluorescence dye. Exonuclease I (Exo I), a sequence-independent nuclease, was selected to digest the single-stranded DNA probe to minimize the background fluorescence signal. As a result, in the absence of the target molecular coralyne, A16 is digested by Exo I from its 3 0 end. This leads to low background fluorescence due to the weak electrostatic interaction between SG I and mononucleotides (dA). On the other hand, the presence of coralyne can induce the single-stranded A16 to form the homo-adenine DNA duplex, and Exo I is inactive to this duplex structure, resulting in a remarkable fluorescence response. Upon background noise reduction, the sensitivity is improved significantly, with a detection limit of 3.5 nM, which is much lower than almost all the previously reported methods. Moreover, this method could extend the application to recognition interaction between ligands and functional nucleic acids and it could find wide applications in the screening of potential therapeutic molecules.

The essential characteristics between highest theoretic capacity and intrinsic volumetric changes hinders the applicable development of Si on high energy/power lithium ion batteries. A novel strategy of building moderate interface linkage combined with preferential three-dimensional structure is put forward by anchoring silicon to conductive matrix by controllable conjugated polar interaction and functional group interaction in our study. A sandwich Si-containing composite of Si@C/rGO with robust polyetherimide "Electron Bridges" is obtained. Polyetherimide is strategically introduced as electron bridges and cross links between conductive matrix and Si nanoparticles with the formation of carbon nanoshell and controllable interface linkage. Beneficially, the architecture effectively provides more electron channels to maintain electrical connectivity, and alleviates the structure collapse to ensure the utilization and the stabilization of silicon materials. This Si@C/rGO anode material exhibits excellent cycling performance with a high reversible capacity of 2048.7 mAh g −1 after 100 cycles. The Coulombic efficiency approaches to 99.8%, and the average capacity loss is only 0.103% per cycle over 500 cycles at 5 C. The optimized confluence of robust interface bonding, stable mechanical structure and excellent electronic connectivity provides a feasible strategy to obtain ultra-long-life silicon anode materials.