Functionalized periodic Au@MOFs nanoparticle arrays as biosensors for dual-channel detection through the complementary effect of SPR and diffraction peaks

A facile and low-cost method to prepare periodic Au@metal-organic framework （MOF） （MIL-100（Fe）） nanoparticle arrays was developed. The arrays were fabricated in situ using monolayer colloidal crystals as templates, followed by Au deposition on substrates, and annealing. MIL-100（Fe） coatings were applied on the nanospheres using a simple solvent thermal process. The prepared periodic Au@MIL-100（Fe） nanoparticle （NP） arrays were characterized by two peaks in the visible spectra. The first peak represented the surface plasmon resonance （SPR） of the Au nanospheres, and the other peak, or the diffraction peak originated from the periodic structure in the NP array. After modification with 3-aminophenylboronic acid hemisulfate （PBA）, the Au@MIL-100（Fe） NP arrays exhibited sensitive responses to different glucose concentrations with good selectivity. These responses could be due to the strong interaction between PBA and glucose molecules. The diffraction peak was sensitive at low glucose concentrations （less than 12 mM）, whereas the SPR peak rapidly responded at high concentrations. The peaks thus demonstrated satisfactory complementary sensitivity for glucose detection in different concentration regions. These results can be used to develop a dual-channel biosensor. We also created a standard diagram, which can be used to efficiently monitor blood glucose levels. The proposed strategy can be extended to develop different dual-channel sensors using Au@MIL-100（Fe） NP arrays agents. functionalized with different recognition

Controllable photodynamic performance via an acidic microenvironment based on two-dimensional metal-organic frameworks for photodynamic therapy

Photodynamic therapy(PDT)is a widely-used technology for cancer therapy,but conventional photosensitizers still face some drawbacks,such as hydrophobicity,inadequate pharmacokinetics,low cell/tissue specificity,and uncontrollable photodynamic performance during the therapeutic process.Herein,we present a controllable photodynamic performance based on two-dimensional metal-organic frameworks(2D Zn-TCPP MOF)that displayed a week PDT effect under a neutral environment upon exposure to a 660 nm laser due to the degeneracy of Q bands of TCPP.However,the 2D Zn-TCPP MOF showed a significantly enhanced PDT effect in an acidic environment under irradiation with a 660 nm laser due to the released TCPP from decomposed MOF structure.From the in vitro outcomes,the 2D Zn-TCPP MOF showed controllable photodynamic performance from neutral to acidic environments.Due to the acidic tumor microenvironment,the 2D Zn-TCPP MOF presented the strongest antitumor effect in vivo under irradiation with a 660 nm laser.This work offers a promising strategy to develop a next-generation photosensitizer.