Magnetic molecularly imprinted polymers using ternary deep eutectic solvent as novel functional monomer for hydroxytyrosol separation.

In this work, magnetic molecularly imprinted polymers (MIPs) for specific recognition of Hydroxytyrosol (HT) were designed by vinyl-modified magnetic particles (Fe3O4@SiO2@VTEOs) as carrier, ternary deep eutectic solvent (DES) as functional monomer, while ethylene glycol dimethacrylate (EGDMA) as crosslinker. The optimum amount of DES was obtained by adsorption experiments (molar ratio, caffeic acid: choline chloride: formic acid = 1:6:3) which were 140 µL in total. Under the optimized amount of DES, the maximum adsorption capacity of the MIPs particles was 42.43 mg g-1, which was superior to non-imprinted polymer (4.64 mg g-1) and the imprinting factor (IF) is 9.10. Syringin and Oleuropicrin were used as two reference molecules to test the selectivity of the DES-MIPs particles. The adsorption capacity of HT was 40.11 mg g-1. Three repeated experiments show that the polymer has high stability and repeatability (RSD = 5.50).

Dual-modified starch nanoparticles containing aromatic systems with highly efficient encapsulation of curcumin and their antibacterial applications.

A series of cinnamic acid (CA)-esterified debranched starch (CDS) containing aromatic systems were prepared and successfully fabricated as nanoparticles to encapsulate curcumin by taking advantage of the additional π-π interactions provided from CA. The CDS nanoparticles (CDS NPs) have good dispersion (polydispersity index of 0.124-0.314) and sizes range of 130-330 nm. The excellent biosafety of CDS NPs was demonstrated by hemolysis, cytotoxicity and mutagenicity assays. Efficient encapsulation (LC = 26.86 %) and sustained release of curcumin were achieved, and the curcumin-encapsulated CDS NPs (CDS-Cur NPs) increased 266-fold water solubility and 2.3-6.5-fold photothermal stability for curcumin, compared to free curcumin. Functional studies showed that CDS-Cur NPs exhibited superior biofilm scavenging ability, with a 2-4.3-fold improvement compared to free curcumin. In addition, CDS-Cur NPs also exhibited far superior antibacterial effects than free curcumin in a bacteriostatic food model of chicken breast. This study not only provides a new scheme for the efficient loading of curcumin, but also provides new ideas for the usage of starch-based materials in antibacterial applications.

New "naked-eye" colori/fluorimetric "turn-on" chemosensor: Ultrafast and ultrasensitive detection of hydrazine in ∼100% aqueous solution and its bio-imaging in living cells.

A new oligothiophene derivative (3TY) was synthesized, and used as a highly selective hydrazine (N2H4) chemosensor in ∼100% aqueous solution with "naked-eye" colorimetric and "turn-on" fluorimetric response. This chemosensor 3TY enabled ultrafast and ultrasensitive detection of hydrazine with ultralow detection limit of 1.45 nM (0.04 ppb) in a wide sensing pH range from 6 to 10. The sensing mechanism of 3TY toward hydrazine was strongly and fully confirmed. More importantly, colorimetric paper test strip and solid support silica are easily prepared by 3TY for on-site and real-time detection of hydrazine. Furthermore, 3TY displays many potential applications for detecting N2H4 in environmental water and human urine along with bio-imaging in living HeLa cells.

Bithiophene-based fluorescent sensor for highly sensitive and ultrarapid detection of Hg2+ in water, seafood, urine and live cells.

Using Hg2+-promoted deprotection reaction, we have developed a new fluorescent turn-on sensor 2TS based on bithiophene fluorophore for Hg2+ detection. The sensing mechanism of 2TS towards Hg2+ was strongly proved by 1H NMR, FTIR, HRMS, UV-vis and fluorescence spectra. Remarkly, 2TS towards Hg2+ in 100% aqueous solution shows high sensitivity with a low detection limit of 19 nM, superior selectivity and ultra-rapid response of 20 s during a wide sensing pH range from 4 to 10. Taking advantage of the excellent properties, the low-cost sensor 2TS-based filter paper/TLC test strips were fabricated for visual, immediate and quantitative detection of Hg2+ in water, proving its applicability towards sensitive in-situ and on-site detection. Meanwhile, 2TS showed high analytical performance for Hg2+ detection in water, seafood as well as human urine samples. Moreover, thanks to the good water solubility, negligible cytotoxicity, good biocompatibility and cell-membrane permeability, 2TS was further applied to effectively image Hg2+ in live cells. Furthermore, the developed sensor 2TS acted as good fluorescent display material for Hg2+ with obvious color change.