Combination of pipette tip solid phase extraction and high performance liquid chromatography for determination of plant growth regulators in food samples based on the electrospun covalent organic framework/polyacrylonitrile nanofiber as highly efficient sorbent.

Facile and sensitive determination of plant growth regulators (PGRs) in food samples is important but still remains great challenge. Herein, a pipette tip solid phase extraction (PT-SPE) method was developed for fast and sensitively detecting PGRs. The PT-SPE adsorbent was prepared by integrating a novel covalent organic framework (COF) of schiff base network 3 (SNW-3) and polyacrylonitrile (PAN) through electrospinning. The SNW-3 can easily adsorb PGRs with high special affinity through electrovalent bands between the ammonium ions of SNW-3 and the carboxy groups of PGRs. The polymer of PAN acts as scaffold material for SNW-3, which can lower seepage pressure hence accelerates adsorption/desorption kinetics. By combination with HPLC-DAD, a satisfactory method was successfully developed for simultaneous determination of ten PGRs in watermelon. Good analytical performances were achieved with this proposed method, including good linearity (5-500 ng/mL) with high correlation coefficients (R ≥ 0.9981), low limits of detection (S/N = 3, 0.24-3.19 ng/mL) and limits of quantification (S/N = 10, 1.65-5.72 ng/mL), satisfactory precision (intra-day RSDs ≤ 2.7%, inter-day RSDs ≤ 3.7%), and high accuracy (recovery: 82.8-113.0%). The method developed in this study shows high potential for design of high target-affinity adsorbents for food sample preparing.

Naphthalimide Derivative-Functionalized Metal-Organic Framework for Highly Sensitive and Selective Determination of Aldehyde by Space Confinement-Induced Sensitivity Enhancement Effect.

Facile and sensitive determination of formaldehyde (FA) in indoor environments still remains challenging. Herein, a fluorescent probe, termed PHN@MOF, was synthesized by embedding the fluorescent molecule of N-propyl-4-hydrazine-naphthalimide (PHN) into a metal-organic framework (MOF) for sensitive and visual monitoring of FA. The hydrazine group of PHN acts as the specific reaction group with FA based on the condensation reaction. The host of MOF (UiO-66-NH2) offers the surrounding confinement space required for the reaction. Owing to the enrichment effect and molecular sieve selection of UiO-66-NH2 to FA, PHN@MOF, compared with free PHN, exhibits very high sensitivity and selectivity based on space confinement-induced sensitivity enhancement (SCISE). Moreover, the fluorescence of UiO-66-NH2 offers a reference signal for FA detection. Using this ratiometric fluorescent PHN@MOF probe, a colorimetric gel plate and test paper were developed and used to visually monitor FA in air.

Highly potent half-sandwich iridium and ruthenium complexes as lysosome-targeted imaging and anticancer agents.

In this study, six half-sandwich luminescent iridium (Ir) and ruthenium (Ru) anticancer complexes bearing P^P-chelating ligands 1,2-bis(diphenylphosphino)benzene (dppbz) and 1,8-bis(diphenylphosphino)naphthalene (dppn) were synthesized and characterized via1H-NMR spectroscopy, 31P-NMR spectroscopy, mass spectrometry, elemental analysis and X-ray crystallography. All the complexes displayed more potent anticancer activity than cisplatin towards A549 lung cancer cells and HeLa cervical cancer cells, especially the most potent iridium complex Ir3, which was 73 times more potent than cisplatin against A549 cells. Different from cisplatin, no nucleobase adducts of Ir3 were detected. With the help of the self-luminescence of complex Ir3 and confocal microscopy, it was observed that Ir3 efficiently penetrated into the A549 cells via energy-dependent active transport, and specifically accumulated in lysosomes, affected the permeabilization of the lysosomal membranes and induced caspase-dependent cell death through lysosomal damage. Both apoptosis and autophagy of the A549 cells were observed. The reactive oxygen species (ROS) elevation, reduction of the mitochondrial membrane potential and cell cycle arrest at the G0/G1 phase also contributed to the observed cytotoxicity of Ir3. We demonstrate that these half-sandwich Ir and Ru anticancer complexes have different anticancer mechanism of action from that of cisplatin, which can be developed as potential multifunctional theranostic platforms that combine bioimaging and anticancer capabilities.