Like surfactants with tunable hydrocarbon chain length, Janus nanoparticles also possess the ability to stabilize emulsions. The volume ratio between the hydrophilic and hydrophobic domains in a single Janus nanoparticle is very important for the stabilization of emulsions, which is still a great challenge. Herein, dual-mesoporous FeO@mC&mSiO Janus nanoparticles with spatial isolation of hydrophobic carbon and hydrophilic silica at the single-particle level have successfully been synthesized for the first time by using a novel surface-charge-mediated selective encapsulation approach. The obtained dual-mesoporous FeO@mC&mSiO Janus nanoparticles are made up of a pure one-dimensional mesoporous SiO nanorod with tunable length (50-400 nm), ∼100 nm wide and ∼2.7 nm mesopores and a closely connected mesoporous FeO@mC magnetic nanosphere (∼150 nm diameter, ∼10 nm mesopores). As a magnetic "solid amphiphilic surfactant", the hydrophilic/hydrophobic ratio can be precisely adjusted by varying the volume ratio between silica and carbon domains, endowing the Janus nanoparticles surfactant-like emulsion stabilization ability and recyclability under a magnetic field. Owing to the total spatial separation of carbon and silica, the Janus nanoparticles with an optimized hydrophilic/hydrophobic ratio show spectacular emulsion stabilizing ability, which is crucial for improving the biphasic catalysis efficiency. By selectively anchoring catalytic active sites into different domains, the fabricated Janus nanoparticles show outstanding performances in biphasic reduction of 4-nitroanisole with 100% conversion efficiency and 700 h high turnover frequency for biphasic cascade synthesis of cinnamic acid.

A near-infrared (NIR) induced decomposable polymer nanocapsule is demonstrated. The nanocapsules are fabricated based on layer-by-layer co-assembly of azobenzene functionalized polymers and up/downconversion nanoparticles (U/DCNPs). When the nanocapsules are exposed to 980 nm light, ultraviolet/visible photons emitted by the U/DCNPs can trigger the photoisomerization of azobenzene groups in the framework. The nanocapsules could decompose from large-sized nanocapsule to small U/DCNPs. Owing to their optimized original size (ca. 180 nm), the nanocapsules can effectively avoid biological barriers, provide a long blood circulation (ca. 5 h, half-life time) and achieve four-fold tumor accumulation. It can fast eliminate from tumor within one hour and release the loaded drugs for chemotherapy after NIR-induced dissociation from initial 180 nm capsules to small 20 nm U/DCNPs.

Despite the importance of nanoparticle’s multipods topology in multivalent-interactions enhanced nano-bio interactions, the precise manipulation of multipods surface topological structures is still a great challenge. Herein, the surface-kinetics mediated multi-site nucleation strategy is demonstrated for the fabrication of mesoporous multipods with precisely tunable surface topological structures. Tribulus-like tetra-pods Fe3O4@SiO2@RF&PMOs (RF = resorcinol-formaldehyde resin, PMO = periodic mesoporous organosilica) nanocomposites have successfully been fabricated with a centering core@shell Fe3O4@SiO2@RF nanoparticle, and four surrounding PMO nanocubes as pods. By manipulating the number of nucleation sites through mediating surface kinetics, a series of multipods mesoporous nanocomposites with precisely controllable surface topological structures are formed, including Janus with only one pod, nearly plane distributed dual-pods and tri-pods, three-dimensional tetrahedral structured tetra-pods, etc. The multipods topology endows the mesoporous nanocomposites enhanced bacteria adhesion ability. Particularly, the tribulus-like tetra-pods mesoporous nanoparticles show ~100% bacteria segregation and long-term inhibition over 90% after antibiotic loading.

Due to the enhanced nano-bio interactions, nanoparticles with a rough surface have attracted a great deal of attention in nanomedicine. However, the low surface area of the rough nanoparticles is not suitable for drug loading. It is still a great challenge to increase the surface area of the nanocarriers without affecting the rough surface architecture. Here, a dual-component asymmetric structured mesoporous ''nanotruck'' is rationally synthesized by the interfacial-energy-mediated anisotropic growth strategy. The nanotruck possesses distinguished dual domains of spherical SiO 2 head with rough surface (rSiO 2 ) as an ''engine'' for enhanced nano-bio interactions, and periodic mesoporous organosilica (PMO) nanorod with a high surface area of $ 794 m 2 /g as a ''trailer'' for efficient drug loading. By embedding a dual-mode up-downconversion luminescent nanoparticle in rSiO 2 head, the nanotrucks exhibit not only unique intensive interaction with tumor cells, long blood circulation and efficient tumor accumulation, but also NIR bio-imaging-guided controllable drug release.

A versatile molecule-mediated interfacial co-assembly strategy has been developed for synthesis of uniform mesoporous N-doped carbon shelled core–shell structures.