Emulsion-Oriented Assembly for Janus Double-Spherical Mesoporous Nanoparticles as Biological Logic Gates

Mesoporous Janus nanoparticles, due to the independent mesoporous compartments, tunable spatial isolated surfaces and compositions, have great application potentials in establishing biological logic systems. However, the reported Janus nanoparticles without large pores are incompatible for the loading of large bio-molecules, limiting their usages as biological logic gates. Herein, an emulsion-oriented assembly approach is demonstrated for the fabrication of highly-uniform Janus double-spherical MSN&mPDA (MSN = mesoporous silica nanoparticle, mPDA = mesoporous polydopamine) nanoparticles with dual large and tunable mesopores. In this novel approach, oil droplets first interact with MSNs to form double-spherical structures, and then orient the selective-encapsulation of mPDA, leading to the final Janus double-spherical MSN&mPDA nanoparticles. The delicate Janus nanoparticle possesses a spherical MSN with a uniform size of ~ 150 nm in diameter, and a mPDA hemisphere with a diameter of ~ 120 nm. The dual-mesoporous nanoparticles possess surface area of ~ 250 m² g⁻¹ and also a high pore volume of ~ 0.56 cm³ g⁻¹. In addition, the mesopore size in MSN compartment is tunable from ~ 3 to ~ 25 nm, while the mPDA compartments possess mesopores with the diameter ranging from ~ 5 to ~ 50 nm. Due to varied chemical properties and mesopore sizes in the two compartments, selective loading of guests in different compartments of the Janus mesoporous nanoparticles can be achieved. Based on such selective loading, single-particle-level biological logic gates with YES, OR and AND logics have been successfully established for the first time. We believe such work paves the way for constructing advanced asymmetric nanomaterials and realizing complex stimuli-responsive systems.