Motivated by recent experimental observations that carbon nanotubes (CNT) can enter animal cells, here we conduct coarse grained molecular dynamics and theoretical studies of the intrinsic interaction mechanisms between CNT's and lipid bilayer. The results indicate that CNT-cell interaction is dominated by van der Waals and hydrophobic forces, and that CNT's with sufficiently small radii can directly pierce through cell membrane while larger tubes tend to enter cell via a wrapping mechanism. Theoretical models are proposed to explain the observed size effect in transition of entry mechanisms.

Lanthanide (such as Tb and Eu) metal–organic frameworks (MOFs) have been widely used in fluorescent probes because of their multiple coordination modes and brilliant fluorescence characteristic. Many lanthanide MOFs were applied in detecting metal ions, inorganic anions, and small molecules. However, it’s rarely reported that Ln-MOF was devoted to detecting malachite green (MG) and uric acid (UA). We prepared a europium-based metal–organic framework (Eu-TDA) (TDA = 2,5-thiophenedicarboxylic acid group). Luminescence studies demonstrated that Eu-TDA can rapidly detect MG and UA with excellent selectivity and sensitivity, where individual quenching efficiency K sv (MG: 5.8 × 105 M–1; UA: 4.15 × 104 M–1) and detection limit (MG: 0.0221 μM; UA: 0.689 μM) were regarded as the excellent MOF sensors for detecting MG and UA. The quenching of Eu-TDA’s fluorescence emission by MG and UA was likely due to the spectral overlap, energy transfer, and competition. Among 11 metal cations and 14 anions, Eu-TDA can quickly and effectively recognize MG and UA with highly selective and sensitive properties. Our method possesses potential application in detecting UA in human blood and MG in the fishpond.

A novel strategy is developed for the fabrication of graphene-CdS (G-CdS) nanocomposites by in situ growth of CdS nanoparticles onto simultaneously reduced graphite oxide, which is noncovalently functionalized by sodium 1-pyrene sulfonate through strong π-π stacking interactions. Subsequently, cobalt 2,9,16,23-tetraaminophthalocyanine (CoTAPc) is self-assembled on the G-CdS nanocomposites through electrostatic interactions to produce phthalocyanine-sensitized G-CdS nanocomposites. The photoactive superstructure enhances the photocurrent generation capability, and presents an efficient photoelectrochemical immunosensing platform for the ultrasensitive detection of the prostate-specific antigen (PSA). The quantitative measurement of PSA is based on the decrease in the photocurrent intensity of the phthalocyanine-sensitized G-CdS nanocomposites, which results from an increase in the steric hindrance due to the formation of the immunocomplex. A linear relationship between the photocurrent decrease and the PSA concentration is obtained in the wide range from 1 pgmL(-1) to 5 μgmL(-1) with a detection limit of 0.63 pgmL(-1). The proposed sensor shows high sensitivity, stability, reproducibility, and can become a promising platform for other biomolecular detection.

Two Eu-based MOF fluorescent sensors, Eu2(CHDA)2(C2O4)(H2O)4 (1) (CHDA = 1,4-cyclohexanedicarboxylic acid, C2O4 = oxalate group) and Eu2(PDA)3(H2O)3 (2) (p-Phenylenediacetic acid = PDA), were prepared for the rapid detection of uric...

Chronic myeloid leukemia (CML) is a malignant clone disease of hematopoietic stem cells. At present, the most effective therapy for CML is bone marrow transplantation, but this procedure is expensive, and it is often difficult to find appropriately matched bone marrow donors. As an alternative to marrow transplantation, a more effective anticancer drug should be developed to cure the disease; in addition, an effective system to evaluate the activity of the drug needs to be developed. Herein, we present a novel antileukemia drug evaluation method based on a multisignal amplified photoelectrochemical sensing platform that monitors the activity of caspase-3, a known marker of cell apoptosis. Manganese-doped CdS@ZnS core-shell nanoparticles (Mn:CdS@ZnS) were synthesized via a simple wet chemical method, which provided a stable photocurrent signal. A DEVD-biotin peptide and streptavidin-labeled alkaline phosphatise (SA-ALP) were immobilized successively at these nanoparticles through amide bonding and through specific interaction between biotin and streptavidin, respectively. The photocurrent of this sensing platform improved as the ALP hydrolyzed the substrate 2-phospho-l-ascorbic acid (AAP) to ascorbic acid (AA), a more efficient electron donor. The activity of caspase-3 was detected using this sensing platform, and thus, the efficacy of nilotinib for targeting K562 CML cells could be evaluated. The results indicate that nilotinib can effectively induce apoptosis of the K562 cells. This sensing platform exhibited sensitive, reproductive, and stable performance in studying the nilotinib-induced apoptosis of K562 CML cells, and the platform could be utilized to evaluate other anticancer drugs.

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Batch adsorption experiments were carried out to remove heavy metal ions such as Cu (II), Ni (II), Cd (II), and Cr (VI) from single-metal solutions using a polyaniline/palygorskite (PP) composite. Different parameters affecting the adsorption capacity such as contact time and pH of the solution have been investigated. The structural characteristics of the PP composite were studied in this work. Atomic absorption spectroscopy was used for the measurement of heavy metal contents, and the adsorption capacity (q e ) calculated were 114 mg Cu (II) g À1 , 84 mg Ni (II) g À1 , 56 mg Cd (II) g À1, and 198 mg Cr (VI) g À1 under optimal conditions. The removal of the metal ions from solutions was assigned to chelation, ionic exchange, and electrostatic attraction. Data from this study proved that the novel organic/inorganic composite presents great potential in the recovery and elimination of noble or heavy metal ions from industrial wastewater.

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