Well-construction of Zn2SnO4/SnO2@ZIF-8 core-shell hetero-structure with efficient photocatalytic activity towards tetracycline under restricted space

Recyclable ZIF-8 inserted boronic acid-modified bacterial nanocellulose microspheres for improved tetracyclines removal from hoggery wastewater

Herein, a novel recyclable composite microsphere PnBC/ZIF-8-CNs was successfully synthesized by incorporating the zeolitic imidazolate framework-8 (ZIF-8) into 3-aminophenylboronic acid modified bacterial nanocellulose microspheres (PnBC-MS). The structural characteristics were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM) as well as element energy X-ray spectroscopy (EDS) mapping, X-ray diffraction (XRD), fourier transform infrared spectrometer (FT-IR), thermogravimetric analysis (TGA), XPS (X-ray photoelectron spectroscopy), and brunauer-emmett-teller (BET). The data showed that adsorption of PnBC/ZIF-8-CNs accorded with the pseudo-first-order kinetic model with spontaneous and endothermic process. The maximum adsorption capacity of tetracycline (1564.44 mg/g) enhanced by 1.2-5 folds compared with other adsorbents containing ZIF-8. The adsorption rate maintained at 81.25 % after five cycles of adsorption-desorption. The practical removal efficiency of tetracycline from real hoggery wastewater by PnBC/ZIF-8-CNs reached 89.77 %. Overall, these features suggested that PnBC/ZIF-8-CNs had simple preparation process, high removal efficiency and good reusability, and it will be a promising adsorbent for the actual antibiotics removal in water.

A novel flower-shaped Ag@ZIF-67 chemiluminescence sensor for sensitive detection of CEA

In this work, a chemiluminescence (CL) aptasensor for sensitive carcinoembryonic antigen (CEA) detection was constructed based on the CL system of luminol-H₂O₂-NaOH. Magnetic carbon nanotubes (MCNTs), as the base material, was modified with CEA-aptamer and DNA1, and was combined with the novel flower-shaped Ag@ZIF-67 of modified with DNA2 through the principle of base complementary pairing. CEA combined with aptamer when it existed in the solution. At the same time, MCNTs was adsorbed at the bottom of the container under the influence of external magnetic field, and Ag@ZIF-67 enhanced the CL signal. The CL aptasensor demonstrated high selectivity and sensitivity for CEA in human serum sample with (1-4): a detection limit of 4.53 × 10^-3 ng/mL in case the detection range was 0.05-500 ng/mL. Furthermore, the proposed method had been shown great potential in cancer diagnosis.