A nonenzymatic electrochemical sensor for the detection of hydrogen peroxide in vitro and in vivo fibrosis models

Fibrosis occurs due to the excessive deposition of extracellular matrix caused by cell injury.After various types of tissue injury,the dysregulation of the internal response can eventually lead to the destruction of organ structure and dysfunction.There is increasing evidence that oxidative stress,which is characterized by excessive production of hydrogen peroxide(H_(2)O_(2)),is an important cause of fibrosis.Therefore,we synthesized a biosensitive and efficient electrochemical H_(2)O_(2)sensor based on PtNi nanoparticle-doped N-reduced graphene oxide(PtNi-N-rGO)to detect H_(2)O_(2)released from transforming growth factorβ1(TGFβ1)-induced myofibroblast.In addition,the sensor could easily detect changes in H_(2)O_(2)in the lung and bronchoalveolar lavage fluid(BALF)of mice with pulmonary fibrosis.Furthermore,the sensor could also detect H_(2)O_(2)in activated hepatic stellate cells and the liver of carbon tetrachloride(CCl_(4))-induced liver fibrosis.Moreover,the alterations in H_(2)O_(2)detected by the sensor were consistent with nicotinamide adenine dinucleotide phosphate oxidase 4(NOX4)protein expression and the staining results of pathological sections.Taken together,these results highlight the use of H_(2)O_(2)sensors for the rapid detection of fibrosis and facilitate the rapid evaluation of antifibrotic drug candidates.

Directional surface plasmon polariton scattering by single low-index dielectric nanoparticles:simulation and experiment

Directionally scattered surface plasmon polaritons(SPPs)promote the efficiency of plasmonic devices by limiting the energy within a given spatial domain,which is one of the key issues to plasmonic devices.Benefitting from the magnetic response induced in high-index dielectric nanoparticles,unidirectionally scattered SPPs have been achieved via interference between electric and magnetic resonances excited in the particles.Yet,as the magnetic response in low-index dielectric nanoparticles is too weak,the directionally scattered SPPs are hard to detect.In this work,we demonstrate forward scattered SPPs in single low-index polystyrene(PS)nanospheres.We numerically illustrate the excitation mechanism of plasmonic induced electric and magnetic multipole modes,as well as their contributions to forward SPP scattering of single PS nanospheres.We also simulate the SPP scattering field distribution obtaining a forward-to-backward scattering intensity ratio of 50.26:1 with 1μm PS particle.Then the forward scattered SPPs are experimentally visualized by Fourier transforming the real-space plasmonic imaging to k-space imaging.The forward scattered SPPs from low-index dielectric nanoparticles pave the way for SPP direction manipulation by all types of nanomaterials.