Temperature-feedback two-photon-responsive metal-organic frameworks for efficient photothermal therapy

The realization of real-time thermal feedback for monitoring photothermal therapy(PTT)under near-infrared(NIR)light irradiation is of great interest and challenge for antitumor therapy.Herein,by assembling highly efficient photothermal conversion gold nanorods and a temperature-responsive probe((E)-4-(4-(diethylamino)styryl)-1-methylpyridin-1-ium,PyS)within MOF-199,an intelligent nanoplatform(AMPP)was fabricated for simultaneous chemodynamic therapy and NIR light-induced temperature-feedback PTT.The fluorescence intensity and temperature of the PyS probe are linearly related due to the restriction of the rotation of the characteristic monomethine bridge.Moreover,the copper ions resulting from the degradation of MOF-199 in an acidic microenvironment can convert H_(2)O_(2)into•OH,resulting in tumor ablation through a Fenton-like reaction,and this process can be accelerated by increasing the temperature.This study establishes a feasible platform for fabricating highly sensitive temperature sensors for efficient temperature-feedback PTT.

Plasmon coupling-driven enhanced high-order multiphoton excited fluorescent performance of metal-organic frameworks

Accessing high-order multiphoton excited fluorescence(H-MPEF)materials is challenging yet and needs complicated synthesis procedures.In this study,we successfully assembled plasmonic Au nanorods(Au NRs)with multiphoton responsive metalorganic frameworks(MOFs),resulting in a significant several-fold enhancement of H-MPEF.The extent of multiphoton enhancement was found to be strongly dependent on the degree of overlap between the multiphoton excitation wavelength of MOFs and the localized surface plasmon resonance absorbance of Au NRs,indicating the importance of plasmon-induced resonance energy transfer.Besides,plasmon-induced hot electron transfer played a vital role in enhanced multiphoton activity as well.Notably,the optimum H-MPEF enhancement occurs at the second near-infrared(NIR-II)region,which provides a promising platform for fluorescent bioimaging.Our findings provide a feasible and practical method to fabricate optimized H-MPEF materials for biological imaging using tissue-penetrating NIR-II light.

Interface boosted highly efficient selective photooxidation in Bi_(3)O_(4)Br/ Bi_(2)O_(3) heterojunctions

Selective photooxidation of amines to biologically important imines is in great demand for industrial applications.The conversion efficiency and selectivity of the process are strongly dependent on the activation of photocatalytic molecular oxygen(O_(2))into reactive oxygen species.Here,we propose the construction of rich interfaces to boost photocatalytic O_(2) activation by facilitating the transfer of photocarriers.Taking Bi_(3)O_(4)Br/Bi_(2)O_(3) heterojunctions as an example,rich interfaces facilitate electron transfer to adsorbed O_(2) for superoxide(O_(2)⋅^(-))generation,thus achieving≥98%conversion efficiency and selectivity for benzylamine and benzylamine derivatives.This study offers a valid method to design advanced photocatalysts for selective oxidation reactions.

Surface modification boosts exciton extraction in confined layered structure for selective oxidation reaction

Extracting photogenerated species from bulk to surface is an essential process for gaining efficient semiconductor-based photocatalysis.However,compared with charged photogenerated carriers,neutral exciton exhibits negligible response to electric field.Accordingly,traditional strategies involving band-alignment construction for boosting directional transfer of charge carriers are impracticable for extracting bulk excitons.To this issue,we here propose that the extraction of bulk exciton could be effectively implemented by surface modification.By taking confined layered bismuth oxycarbonate(Bi_(2)O_(2)CO_(3))as an example,we highlight that the incorporation of iodine atoms on the surface could modify the micro-region electronic structure and hence lead to reduced energy of surface excitonic states.Benefiting from the energy gradient between bulk and surface excitonic states,iodine-modified Bi_(2)O_(2)CO_(3)possesses high-efficiency bulk exciton extraction,and hence exhibits promoted performance in triggering1 O2-mediated selective oxidation reaction.This work presents the positive role of surface modification in regulating excitonic processes of semiconductor-based photocatalysts.