Dynamic DNA nanodevices have gained tremendous attention due to their extraordinary inherent functionality and advantages, however, dynamic DNA nanodevices-based biosensors are still challenging due to their high reliance on proteases and limited amplification capabilities. Herein, exploiting bispecific aptamer as initiators for the first time, we developed a three-dimensional (3D) DNA nanomotor biosensor powered by DNAzyme and entropy-driven circuit for sensitive and specific detection of lysozyme, in which walking and rolling strategies are efficiently integrated to achieve excellent signal amplification capability. Benefiting from the high selectivity of bispecific aptamer, the 3D DNA nanomotor biosensor can respond to lysozyme with high specificity and operate at high speed to release signals. The whole process is independent of protease, avoiding the influence of adverse environment on the operation stability. Under optimal conditions, it can achieve a limit of detection as low as 0.01 pg/mL with an excellent linear range of 0.05 pg/mL–500 ng/mL for lysozyme. Furthermore, the proposed strategy revealed high accuracy in the analysis of real samples, indicating a great potential for the application of nanomotor biosensors to the detection of non-nucleic acid targets.

Herein, we report the fabrication of Fe₃O₄@TiO₂ nanosheet/Ag/g-C₃N₄ (Fe₃O₄@ns-TiO₂/Ag/g-C₃N₄) composite photocatalysts with well-designed hierarchical yolk-shell structure. To endow the composites with fascinating features, multiple functional components are perfectly integrated into the definite structure. The photodegradation experiments of organic pollutants revealed a significant enhancement in photocatalytic activity of developed composites as compared to P25, which is mainly due to the synergetic interaction of the tailored three-dimensional (3D) yolk-shell porous nanostructure, extended sunlight response range, and retarded the recombination probability of photogenerated electrons-holes. More importantly, the hybrid samples exhibited superior magnetic properties due to the magnetic component. The excellent magnetic recyclability and reusability of the photocatalysts are verified by the magnetic hysteresis loop and cyclic photocatalytic degradation experiments, which is significant for the green and sustainable applications of photocatalysts. Considering its remarkable photocatalytic performance and expectant magnetic recyclability, the composite photocatalysts are expected to be a promising candidate to dispose of future environmental issues.