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An APTES-functionalized magnetic core–immobilized enzyme drives the formation of an acid-sensitive ZIF-8 shell via biomineralization growth, which offers a spontaneous dual–endogenous stimulus-responsive modal enzyme catalytic-chemotherapy for HeLa tumor cells. Herein, the ZIF-8 shell plays a dual role in the combination therapy, i.e., protecting activities of embedded enzymes and loading therapeutic agents into the framework. In order to enhance the efficiency of enzyme therapy, a biocascade reaction in confined space via two types of embedded enzymes under endogenous glucose stimuli was performed, which promotes continuous consumption of endogenous glucose, leading to starvation of tumor cells. Simultaneously, the inherent acidic tumor microenvironment and gluconic acid produced from endogenous glucose oxidation can gradually dissociate the ZIF-8 shell with the aid of pH-stimulus-responsive mode to enhance endo-lysosomal escape for releasing therapeutic agents to effectively induce apoptosis of tumor cells. The recovery of the magnetic core can regenerate multifunctional nanoplatforms for achieving circulation therapy of tumor cells. [ABSTRACT FROM AUTHOR]

Fe3O4@SiO2@Ag magnetic–plasmonic nanospindles with efficient SERS performance and magnetic responsiveness have been successfully fabricated. Uniform and monodispersed Fe3O4@SiO2 nanospindles were prepared by a robust strategy through annealing the obtained β-FeOOH@SiO2 nanospindles in hydrogen atmospheres at 350 °C; the SiO2 shell could be regarded as an interlayer to maintain the morphology and offer a solid support for the further growth of Ag nanoparticles. Ag nanoparticles were introduced via in situ reduction of AgNO3, and the coverage rate of Ag nanoparticles anchored on Fe3O4@SiO2 was adjusted through regulating the AgNO3 concentration. Fe3O4@SiO2@Ag magnetic–plasmonic nanospindles can serve as highly efficient SERS active substrates with controllable magnetic aggregation due to steady enrichment of mass molecules in close proximity to abundant hot spots. Moreover, these nanospindles are used for label-free detection of thiram, and the detection limit is as low as 1 × 10−7 M (about 0.024 ppm), which is lower than the maximal residue limit of 7 ppm in fruits prescribed by the U.S. Environmental Protection Agency. Therefore, such magnetic–plasmonic nanospindles in the magnetic aggregation state may be potentially applied in rapid trace detection of residual pesticides or other specific analytes. [ABSTRACT FROM AUTHOR]