Xue Tian,Peng Zhang,Yizhi Liao,Razium A. Soomro,Bin Xu
Antimony-based anode materials are recognized for their high potassium storage capacities and appropriate operating potentials. However, the large volume expansion of Sb during the potassiation/depotassiation process, which results in a quick capacity decay, severely limits its practical application in potassium-ion batteries (PIBs). Here, a carbon-coated Sb/MXene heterostructure composite (CSM) is synthesized by adsorption of Sb 3+ on MXene nanosheets via Sb-O-Ti bonds followed by carbothermic reduction to construct dual-confined MXene@carbon conductive framework capable of withstanding high volume expansion of Sb and conducive to enabling accelerated electron transfer kinetics. The CSM composite, particularly CSM-700, when configured as an anode for PIBs, realized high capacity (484.4 mAh g −1 at 0.1 A g −1 ), an ultra-stable cycling performance with a high reversible capacity of 435.9 mAh g −1 at 0.1 A g −1 after 100 cycles corresponding to a capacity retention rate of 90.0%, and superior rate performance of 323.0 mAh g −1 at 1 A g −1 . The proposed strategy offers a simple route to construct high-performance Sb-based anodes for advanced PIBs.
DNA walkers have been widely used to build biosensing systems. However, their moving efficiency was limited, which has hindered practical applications. Here, we for the first time integrated localized CHA with nanoscale AuNPs scaffolds to achieve space double-confined catalytic hairpin assembly (SDCHA) for developing a fast three-dimensional DNA walker. Driven by spatially proximal displacement, the walker possessed a high walking speed, which was about 8 times, 9 times and 23 times faster than LCHA, CHA-AuNPs and conventional CHA, respectively. Moreover, the walking time was about 1.4–8.3 times shorter than most recently reported DNA walkers and space-confined strand displacement reactions. By further integrating it with magnetic probes and g-C 3 N 4 nanosheets , an ultrasensitive and enzyme-free homogeneous electrochemiluminescence (Ho-ECL) aptasensor was firstly constructed for sonic hedgehog (SHh) detection. Profiting from this tailored integration, the Ho-ECL aptasensor avoided multiple interferences from complex milieu as well as tedious procedures of electrode modifying and washing, showing good signal stability, repeatability and reliability. It was also proved to achieve ultrasensitive SHh detection with the detection limit as low as 13.5 fM, superior to previous research on SHh detection. This work might broaden ideas for the construction of fast DNA walkers and facile Ho-ECL bioanalytical methods for clinical diagnosis.
Synthetic catalytic DNAzyme circuits have gained great attention as versatile theranostic toolboxes, but their accuracy and efficiency is restricted by uncontrolled signal leakage and inefficient circuitry activation. Here, a trinity DNAzyme circuit (TriDC) is constructed using a unique logic gate bioswitchable DNA tetrahedral walker@MnO 2 nanosheets structure. The AND logic gate bioswitchable DNA tetrahedral walker, composed of dual allosteric DNAzyme (termed “commander” and “soldier”) and tetrahedral scaffold, is used to execute imaging-guided gene therapy by avoiding undesired signal leakage and cascade “walking” in a confined space. Glutathione-mediated reduction of MnO 2 nanosheets provides secondary confinement to stack the DNA tetrahedral walker in situ, offering abundant Mn 2+ as a cofactor to achieve self-sufficiency of DNAzyme circuits and induce chemo-dynamic therapy. The structure increases local reaction concentrations by ≈100-fold according to the collision frequency model, enabling the AND logic detection of microRNA-10b and microRNA-155 at a limit of detection of 98.97 p m , thereby facilitating the precise imaging of breast cancer cells. The combined gene/chemo-dynamic therapy achieves 66.2% tumor growth inhibition efficiency. The TriDC offers novel insights into tumor theranostics and also presents a paradigm for the in situ implementation of higher-order DNAzyme circuits.
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