Organic fluorescent probes are widely used in bioimaging and bioassays, but the notorious photobleaching hampers their applications. Encapsulation of organic dyes into nanoparticles (NPs) is an effective strategy to minimize photobleaching, but classical organic dye molecules tend to have their fluorescence quenched in aggregate states, which is termed aggregation-caused quenching (ACQ). Here we demonstrate our attempt to tackle this problem through the aggregation-induced emission (AIE) strategy. 3,4:9,10-Tetracarboxylic perylene bisimide (PBI) is a well-known organic dye with a serious ACQ problem. By attaching two tetraphenylethene (TPE) moieties to the 1,7-positions, the ACQcharacteristic PBI-derivative was converted to an AIE-characteristic molecule. The obtained PBI derivative (BTPEPBI) exhibits several advantages over classical PBI derivatives, including pronounced fluorescence enhancement in aggregate state, red to near infrared emission, and facile fabrication into uniform NPs. Studies on the staining of MCF-7 breast cancer cells and in vivo imaging of a tumorbearing mouse model with BTPEPBI-containing NPs reveal that they are effective fluorescent probes for cancer cell and in vivo tumor diagnosis with high specificity, high photostability and good fluorescence contrast.
Poly(3-heptylselenophene)-stat-poly(3-hexylthiophene) is synthesized and characterized in terms of its crystallinity and performance in an organic photovoltaic (OPV) cell. Despite the random distribution of units along the polymer main chain, the material is semi-crystalline, as demonstrated by differential scanning calorimetry and wide-angle X-ray diffraction. Thin-film absorption suggests an increased compatibility than seen with 3-hexylselenophene monomer. Optoelectronic properties are an average of the two homopolymers, and OPV performance is enhanced by a broadened absorption profile and a favorable morphology.
In this paper, we report a facile method to prepare high-yield one dimensional hierarchical β-Co(OH) 2 nanocolumns through one-step hydrothermal synthesis with hydrazine hydrate and Na 3 PO 4 as morphologydirecting agents, which play important roles in the formation of hierarchical nanocolumn morphology. The hierarchical Co 3 O 4 nanocolumns are obtained by the β-Co(OH) 2 nanocolumns annealed at 400 °C for 4 h. The formation mechanism of hierarchical nanocolumns has been clearly demonstrated by studying morphology evolution processes of β-Co(OH) 2 nanocrystals upon reaction time, which undergo two steps, the formation of nanorods and then growing sideways in the form of thin nanoplatelets to form hierarchical nanocolumns. Moreover the UV-vis spectra and magnetic properties of Co 3 O 4 nanocolumns also have been investigated.
Here, two novel 3D Cd(II)-MOFs, [Cd3·L·(BTB)2·2DMF]
and [(Cd3O2)·L·BTC] (denoted
as CUST-532 and CUST-533, L = 9,10-bis(N-benzimidazolyl)-anthracene, BTB = 1,3,5-tris(4-carboxyphenyl) benzene, BTC = 1,3,5-benzenetricarboxylic acid, CUST = Changchun University of
Science and Technology), were synthesized by solvothermal conditions.
Both CUST-532 and CUST-533 are 3D (3,8)-c
topological nets with the same point symbol of {43}2{46·618·84}. PXRD
and TGA analyses prove that CUST-532 and CUST-533 have good structural stability and thermal stability. On the basis
of the high fluorescence characteristics, the results of fluorescence
sensing experiments show that CUST-532 and CUST-533 can be used as multifunctional chemical sensors to achieve rapid
fluorescence quenching response to antibiotic residues, Fe3+ and Cr2O7
2– ions at a much
lower concentration. Furthermore, the possible mechanisms of fluorescence
quenching in the sensing process were systematically studied by PXRD,
UV–vis, fluorescence decay lifetime, and density functional
theory.
A 2-hydroxyazobenzene platform has been evaluated to photorelease protons in aqueous solutions. Three different systems relying on molecular, supramolecular and polymeric strategies have been investigated in order to tune the water solubility and the thermodynamic and kinetic properties. This paper first reports on the syntheses and the physico chemical analyses for each system. Subsequently, we show that the three strategies are appropriate to reversibly photo-generate tunable pH drops in water up to one pH unit amplitude and at the 10-100 s timescale, upon transient illumination at 365 nm.
Cisplatin has become one of the most commonly used compounds for the treatment of a wide spectrum of human malignancies. Unfortunately, cisplatin has several major drawbacks. Driven by the impressive impact of cisplatin on cancer chemotherapy, great efforts have been made to develop new derivatives with improved pharmacological properties. Among the over 30 platinum agents which have entered clinical trials after the onset of clinical studies with cisplatin in the early 1970s, only carboplatin and oxaliplatin have received worldwide approval so far, nedaplatin, lobaplatin and heptaplatin have gained regionally limited approval. It has become quite evident that mere analogues of cisplatin or carboplatin will not probably offer any substantial clinical advantages over the existing drugs. Therefore, people turned to synthesize non-classical platinum anticancer drugs which were capable of forming a different range of DNA adducts which could display a different spectrum of anticancer activity compared to cisplatin. This review will summarize the structural types and structure-activity rules of non-classical bi- and multi-nuclear platinum anticancer drugs, and discuss their future potential as anticancer agents.
By rational in situ crystallization, HKUST-1 embedded in a chitosan film exhibits reduced cytotoxicity and restricted copper release, inducing enhanced infectious wound therapy.
The water sensitivity of metal-organic frameworks (MOFs) poses a critical issue for their large-scale applications. One effective method to solve this is to provide MOFs with a hydrophobic surface. Herein, we develop a facile solution-immersion process to deposit a hydrophobic coating on the MOFs' external surface without blocking their intrinsic pores. The water contact angle of the surface hydrophobic (SH) MOFs is ∼146°. The hydrophobic coating not only greatly enhances MOFs' water stability but also provides durable protection against the attack of water molecules. When exposed to liquid water, the SH samples well retain their crystal structure, morphology, surface area and CO uptake capacity. However, the as-synthesized (AS) samples nearly collapse and lose their porosity as well as CO uptake capacity after the same exposure. This study opens up a new avenue for the MOFs' application of gas sorption in the presence of water.
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