Preparation, characterization and luminescent properties of dense nano‐silica hybrids loaded with 1,8‐naphthalic anhydride

Abstract

Novel luminescent dense nano-silica hybrid materials (DNSS) modified with different amounts of (3-aminopropyl)triethoxysilane (APTES) and 1,8-naphthalic anhydride (NA) were successfully synthesized via two steps combined with post-grafting methods. Powder X-ray diffraction (XRD), N2-sorption analysis, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), photoluminescence (PL) spectroscopy and elemental analysis, as well as time-resolved decays were employed to characterize the resultant hybrid materials. The results revealed that luminescent organic molecules had been successfully loaded onto the amine-modified surface of nano-silica spheres. In addition, their fluorescence intensity and characteristic peak of emission spectra changed with increasing amount of APTES and NA additive. In particular, the characteristic peak showed a red shift from 390 to 450 nm, however, this was inconsistent with results calculated on the basis of the elemental analysis data, most probably because of the dispersion behaviors of NA molecules from the aggregating to the monolayer state. These observations demonstrated the existence of a quantum confinement effectiveness of NA-DNSS samples, and therefore a possible mechanism was put forward.

Multifunctional Mesoporous CDQs/BMMs with Strong Fluorescent Property and Sustained Drug Releasing Performance

“…The FT‐IR spectra of all related samples are shown in Figure A, which exhibited the characteristic bands of mesoporous silica‐based frameworks centered at about 458, 800, and 1076 cm −1 , corresponding to asymmetric and symmetric Si−O stretching vibrations . However, as shown in Figures A‐c and d, the appearance of additional peaks located at 2850 and 2928 cm −1 were attributed to C−H stretching vibrations, further indicating the incomplete removal of CTAB in CBI and CBA.…”

“…elucidated the excitation wavelength‐dependent effect with a broad range emission from visible region to near‐infrared region. Additionally, Figure B(inset) exhibited the fluorescence emission spectra of various diluted CQDs solutions, showing a stable peak at 440 nm, suggesting the CQDs existences as monodisperse state in the diluted solutions …”

“…investigated the influences of the used solvent polarity (acetone, methanol, DMF, acetonitrile, and DMSO) and various anions (Cl − , NO 3 − , and C 6 H 5 O 7 3− ) on the luminescent property of 1,8‐naphthalicanhydride (NA)‐grafted the mesoporous surface of silica, showing the red‐shift occurrences of emission peak along with the aggregation behaviors of NA via turning the concentration. Recently, we prepared the hybrid materials via grafting NA on the bimodal mesopores silicas (BMMs), indicating a promising drug carrier with high drug‐loading capacity and controlled drug delivery . However, their luminescent intensity was slightly low due to the leaching of grafted‐NA from drug‐loaded matrix during the loading and releasing periods …”

Nucleation and Assembly of Silica into Protein-Based Nanocomposites as Effective Anticancer Drug Carriers Using Self-Assembled Silk Protein Nanostructures as Biotemplates

“…29–31 We chose HeLa cells as model cancer cells to study the cellular uptake of silica composites. The cells were cultured in DMEM and supplemented with 10% FBS and 1% penicillin-streptomycin.…”

Multifunctional Mesoporous ZnO@BMMs with Strong Fluorescence and High Loading Capacity for Controlled Drug Delivery

“…However, how to track and detect the effectiveness of the drug release behavior in vivo is presently one of main challenges, as the adsorption or diffusion of the drug in the confined mesoporous matrix has not been essentially investigated. For these reasons, many researchers focused on the grafting luminescent molecules into the mesoporous surface of silica‐based matrix so as to assess the pharmacokinetic behavior of loaded drug by capturing its fluorescence signal …”