Multifunctional nanocomposites have the potential to integrate sensing, diagnostic, and therapeutic functions into a single nanostructure. Herein, we synthesize Fe 3 O 4 @polydopamine core-shell nanocomposites (Fe 3 O 4 @PDA NCs) through an in situ self-polymerization method. Dopamine, a melanin-like mimic of mussel adhesive proteins, can self-polymerize to form surface-adherent polydopamine (PDA) films onto a wide range of materials including Fe 3 O 4 nanoparticles used here. In such nanocomposites, PDA provides a number of advantages, such as near-infrared absorption, high fluorescence quenching efficiency, and a surface for further functionalization with biomolecules. We demonstrate the ability of the Fe 3 O 4 @PDA NCs to act as theranostic agents for intracellular mRNA detection and multimodal imaging-guided photothermal * Address correspondence to hhyang@fio.org.cn, gangliu.cmitm@xmu.edu.cn.. Conflict of Interest:The authors declare no competing financial interest. Supporting Information Available:Additional information as noted in the text. This material is available free of charge via the Internet at http://pubs.acs.org. Messenger RNA (mRNA), a single-stranded ribonucleic acid, is also the blueprint for the cellular production of proteins. Moreover, some mRNAs are disease-relevant and can be utilized as markers to determine the stage of the disease. 22 Recently, several methods such as microarray analysis 23 and real-time polymerase chain reaction (RT-PCR) 24 have been developed for mRNA detection. Although these methods are effective for detecting mRNA expression in bulk samples, they are incapable of identifying cell-to-cell mutations. Significantly, many important biological processes not only are related with bulk mRNA expression, but also rely highly on cell-to-cell variations in mRNA. 25 Thus, it is necessary to develop useful approaches for detecting mRNA in living cells. [26][27][28][29][30][31][32] In this work, we fabricated multifunctional Figure 1a). Furthermore, we demonstrated that PDA can adsorb dye-labeled singlestranded DNA (ssDNA) probe and effectively quench the fluorescence of the dye. In the presence of the target, the specific binding between the dye-labeled ssDNA probe and its Figure 1c). Our results suggest a high potential for the use of PDA in the construction of multifunctional nanocomposites for simultaneous diagnosis and therapy of cancer. HHS Public Access RESULTS AND DISCUSSIONFe 3 O 4 NPs were easily coated with a uniform PDA shell by dispersing them in an alkaline DA solution and mildly shaking at room temperature for 4 h. Transmission electron microscopy (TEM) revealed that approximately a 4 nm thick PDA shell was wrapped on the surface of the Fe 3 O 4 NPs after self-polymerization of the DA ( Figure 2a). The dynamic light scattering (DLS) data showed that the hydrodynamic diameter of the Fe 3 O 4 NPs was increased after the PDA coating (Supporting Information Figure S1), which is consistent with the TEM results. Moreover, the Fe 3 O 4 @PDA NCs exhibited excelle...

We report a type of photosensitizer (PS)-loaded micelles integrating cyanine dye as potential theranostic micelles for precise anatomical tumor localization via dual photoacoustic (PA)/near-infrared fluorescent (NIRF) imaging modalities, and simultaneously superior cancer therapy via sequential synergistic photothermal therapy (PTT)/photodynamic therapy (PDT). The micelles exhibit enhanced photostability, cell internalization and tumor accumulation. The dual NIRF/PA imaging modalities of the micelles cause the high imaging contrast and spatial resolution of tumors, which provide precise anatomical localization of the tumor and its inner vasculature for guiding PTT/PDT treatments. Moreover, the micelles can generate severe photothermal damage on cancer cells and destabilization of the lysosomes upon PTT photo-irradiation, which subsequently facilitate synergistic photodynamic injury via PS under PDT treatment. The sequential treatments of PTT/PDT trigger the enhanced cytoplasmic delivery of PS, which contributes to the synergistic anticancer efficacy of PS. Our strategy provides a dual-modal cancer imaging with high imaging contrast and spatial resolution, and subsequent therapeutic synergy of PTT/PDT for potential multimodal theranostic application.

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As a promising cell tracking technology, 19F MRI suffers from low sensitivity. Here, fluorinated nanoemulsions with a unified 19F signal and paramagnetic relaxation enhancement were developed as 19F MRI cellular tracers with high stability, size controllability, biocompatibility, cellular uptake, and dual-modality for sensitive in vivo RAW264.7 cell tracking.

For detecting metal ions with F chemical exchange saturation transfer magnetic resonance imaging (F CEST MRI), a class of novel fluorinated chelators with diverse fluorine contents and chelation properties were conveniently synthesized on gram scales. Among them, a DTPA-derived chelator with high sensitivity and selectivity was identified as a novel F CEST imaging probe for simultaneously detecting multiple metal ions.

Electro-Fenton is a promising advanced oxidation process for wastewater treatment. In this study, mesoporous carbon grafted activated carbon fibers (ACF@OMC) with different pore size were fabricated by using boric acid as the expanding agent. To study the pore structure and pore size effect on the electro-Fenton (E-Fenton) efficiency of ACF@OMC cathode materials, disordered mesoporous carbon grafted activated carbon fibers (ACF@DMC) were also prepared, and both anionic dye (Orange II) and cationic dye (Rhodamine B) were selected as target organic pollutants. Meanwhile, electro-induced generation rates of hydrogen peroxide and hydroxyl radical were measured. It was found that the E-Fenton efficiency of the cathode materials follows the increasing order of ACF@DMC <

Nitrogen-doped ordered mesoporous carbon (N-OMC) was successfully prepared using dicyandiamide (C 2 H 4 N 4 ) as the nitrogen source and was grafted onto activated carbon fibres (ACFs) to form carbon composites (ACF@N-OMC). The resultant ACF@N-OMC materials were used as a cathode for the electro-Fenton degradation of organic pollutants using Brilliant Red X3B as a molecular probe. Our prepared ACF@N-OMC materials showed a higher electrocatalytic activity than nitrogen-free carbon materials. The doped nitrogen ACF@N-OMC cathode materials reduced the overpotential of O 2 reduction in the cathode. In addition, the introduction of nitrogen into the ACF@N-OMC materials resulted in a larger pore size, which was beneficial for O 2 diffusion, producing more reactive species.The electrocatalytic activity of the ACF@N-OMC cathode materials depends on the nitrogen content.With an increase in the nitrogen content, the activity first increased and then decreased. The ACF@N-OMC materials were stable and could be reused at least six times in the electro-Fenton degradation of Brilliant Red X3B without a significant loss of activity.

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