Nanoformulations that can respond to the specific tumor microenvironment (TME), such as a weakly acidic pH, low oxygen, and high glutathione (GSH), show promise for killing cancer cells with minimal invasiveness and high specificity. In this study, we demonstrate self-assembled copper−amino acid mercaptide nanoparticles (Cu-Cys NPs) for in situ glutathione-activated and H 2 O 2 -reinforced chemodynamic therapy for drugresistant breast cancer. After endocytosis into tumor cells, the Cu-Cys NPs could first react with local GSH, induce GSH depletion, and reduce Cu 2+ to Cu + . Subsequently, the generated Cu + would react with local H 2 O 2 to generate toxic hydroxyl radicals (•OH) via a Fenton-like reaction, which has a fast reaction rate in the weakly acidic TME, that are responsible for tumor-cell apoptosis. Due to the high GSH and H 2 O 2 concentration in tumor cells, which sequentially triggers the redox reactions, Cu-Cys NPs exhibited relatively high cytotoxicity to cancer cells, whereas normal cells were left alive. The in vivo results also proved that Cu-Cys NPs efficiently inhibited drug-resistant breast cancer without causing obvious systemic toxicity. As a novel copper mercaptide nanoformulation responsive to the TME, these Cu-Cys NPs may have great potential in chemodynamic cancer therapy.

Over the past decades, water-soluble conjugated polymers (CPs) have gained increasing attention as optical platforms for sensitive detection of biomacromolecules (DNA, protein and cell) due to the amplification of fluorescent signals. To meet the requirement for high throughput assays, chip and microarray techniques based on CPs have also been developed. Very recently, fluorescence imaging in vivo and at the cellular level have also been successfully accomplished using these water-soluble CPs. In this tutorial review, we provide a brief review of the synthesis and optical properties of CPs, focusing especially on their applications in biosensors and cell imaging.

Cationic water-soluble conjugated polymers with a non "rigid-rod" aspect ratio can be prepared by Suzuki coupling condensation polymerization of 2,7-dibromo-9,9-bis(6'-bromohexyl)fluorene and varying ratios of p- and m-phenyl diboronic acids, followed by reaction with trimethylamine. The resulting polymers are designated MnPm+, where the subscripts in Mn and Pm correspond to the ratio of meta and para linkages, respectively. Absorption and fluorescence spectra indicate facile energy transfer via interachain or intrachain mechanisms. The emission of MnPm+ with m > 50 matches that of M0P100+. Excitations ultimately reside in the polymer segments with largest number of para linkages. FRET experiments show that the polymers with a more flexible structure are better donors to fluorescein-labeled double-stranded DNA. Similar results are obtained when intercalated ethidium bromide is used as the acceptor. These results indicate that there is better spatial registry between the flexible conjugated polymers and the secondary structure of DNA.

P-N junctions are of great importance both in modern electronic applications and in understanding other semiconductor devices. Organic/inorganic P-N junction nanowires composed of functional organic molecules and inorganic molecules may be able to realize new or improved chemical and physical properties that were not observed in the individual component on nanosize and their bulk materials. We report herein the fabrication of the organic/inorganic semiconductor P-N junction nanowire and the remarkable performance on the light-controlled diode within a single hybrid P-N junction nanowire. Controlling the conductivity of the P-N junction nanowire by the light irradiation simply to achieve diode work indicates a new way to realize the photoelectric integration in a single nanowire device.

Water‐soluble conjugated polymers have attracted much attention in the biosensor community because of recent exciting experimental results. The transfer of excitation energy along the whole backbone of the conjugated polymer to the reporter results in an amplified fluorescence signal, which makes them useful as optical platforms in highly sensitive chemical and biological sensors. In this Research News Article, we provide a brief review of recent developments in this field, focusing especially on the application of water‐soluble optical conjugated polymers in biomacromolecule (DNA and protein) detection.

Conjugated polymers (CPs) attract a lot of attention in sensing, imaging, and biomedical applications because of recent achievements that are highlighted in this Research News article. A brief review of recent progress in the application of CP-based energy-transfer systems in antimicrobial and anticancer treatments is provided. The transfer of excitation energy from CPs to photosensitizers leads to the generation of reactive oxygen species (ROS) that are able to efficiently kill pathogenic microorganisms and cancer cells in the surroundings. Both fluorescence resonance energy transfer (FRET) and bioluminescence energy transfer (BRET) modes are discussed.

A visible near-infrared chemosensor (MCy-1) for mercury ions was successfully devised and characterized. A large red-shift (122 nm) of the absorption maximum of MCy-1 was observed. An important feature for the new chemosensor is its high selectivity towards mercury ions over the other competitive species, making the "naked-eye" detection of mercury ions possible.

enced by changing the choice, amount and ratio within each CPN. [ 7,26 ] Additionally, as single multicolor CPNs can be tuned to match the different excitation sources of commercial optical instruments, such as fl uorescence spectrometers, fl uorescence microscopes, and in fl ow cytometry.In this work, we describe the design and synthesis of four conjugated polymers with blue, green, yellow and red emissions, and used them to prepare carboxyl functionalized CPNs by a co-precipitation method based on hydrophobic interactions between the conjugated polymers and poly(styreneco -maleic anhydride) (PSMA). [ 6,27 ] The carboxyl functionalized CPNs can also be prepared by co-precipitation of four conjugated polymers with PSMA, which show multicolor emissions by under single excitation wavelength. CPNs were modifi ed with primary antibody to obtain CPNs-antibody conjugates. In comparison to single antibody recognition, higher specifi city for tumor cells detection was achieved by binding two CPNs labeled with different antibodies to a single tumor cell. Finally, we show that the multicolor CPNs can match different excitation sources of fl uorescence microscopy and fl ow cytometry to achieve straightforward cell imaging and detection.Four π-conjugated polymers (P1 ∼ P4) were obtained by Suzuki cross-coupling polymerization of monomers 1 -4 with monomer 5 [ 17,28 ] in yields of 15∼48% ( Scheme 1 a). Absorption and fl uorescence characteristics were determined in CHCl 3 and show that each polymer spans a different region of the visible spectrum (Table S1). Compared with the corresponding monomers, the absorption spectra of P1∼P4 ( Figure S1) not only have characteristic absorptions of monomers but also exhibit new combination absorptions with the increase of aromatic heterocyclic units. In these polymers, the absorptions in shorter wavelength region originate from the fl uorene units, and the longer absorptions lie in the signal aromatic heterocyclic unit or cooperative actions of different monomers. The emission spectra show maxima for P1, P2, P3 and P4 are 422, 500, 540 and 670 nm, respectively. Emission quantum yields (QY) vary depending on the electron acceptor unit in the polymer backbones (3 ∼ 78%). Upon excitation at 360 nm, the shorter wavelength-emissive polymers were anticipated to act as the donor for longer wavelength-emissive ones (acceptors), through interchain multi-step FRET. Thus, by varying the mixing ratio of the polymers, multicolor emission can be regulated through FRET among the four polymers under one excitation wavelength. In order to achieve bioconjugation, CPNs are required to provide surface functional groups (such as -COOH, -NH 2 , -N 3 , -C≡CH, etc.) for subsequent modifi cation. Herein, such CPNs with carboxyl groups on the surface were prepared by a modifi ed co-precipitation method [ 6,27 ] based Conjugated polymer nanoparticles (CPNs) combine the properties of conjugated polymers (CPs) and nanoparticles and defi ne a new class of promising fl uorescence materials that are being integrated in...