Fabrication of Hypericin Imprinted Polymer Nanospheres via Thiol-Yne Click Reaction

Abstract

Abstract:To fabricate molecularly imprinted polymer nanospheres via click reaction, five different clickable compounds were synthesized and two types of click reactions (azide-alkyne and thiol-yne) were explored. It was found that molecularly imprinted polymer nanospheres could be successfully synthesized via thiol-yne click reaction using 3,5-diethynyl-pyridine (1) as the monomer, tris(3-mercaptopropionate) (tri-thiol, 5) as the crosslinker, and hypericin as the template (MIP-NSHs). The click polymerization completed in merely 4 h to produce the desired MIP-NSHs, which were characterized by FTIR, SEM, DLS, and BET, respectively. The reaction conditions for adsorption capacity and selectivity towards hypericin were optimized, and the MIP-NSHs synthesized under the optimized conditions showed a high adsorption capacity (Q = 6.03 µmol·g −1 ) towards hypericin. The imprinting factors of MIP-NSHs towards hypericin, protohypericin, and emodin were 2.44, 2.88, and 2.10, respectively.

Fabrication of Silicon Carbide from Recycled Silicon Wafer Cutting Sludge and Its Purification

“…The Si sludge shows peaks at 618 cm −1 ,1065 cm −1 , 800 cm −1 , 1134 cm −1 , 1225 cm −1 , and 2124 cm −1 , which belong to Si-O-Si, Si-O, Si-O-C, Si-Si, and C≡C bonds, respectively. This analysis showed similarities with other analyses indicating that the Si sludge contains a little amount of C and O. SiC synthesized at the optimum condition showed peaks at 760 cm −1 , 1047 cm −1 , and 2110 cm −1 , corresponding to Si-O, Si-O-C, and C≡C bonds [29][30][31][32][33]. Both Si sludge and synthesized SiC contain carbon in the samples with trace amounts of oxide.…”

The Effect of Monomers on the Recognition Properties of Molecularly Imprinted Beads for Proto-hypericin and Proto-pseudohypericin

“…Further on, Figure 5 (c) shows that the highest imprinting factors, IF were registered for the same MIP AA-IA system (meaning IFProto-PH = 4.63, IFPH = 2.44, IFProto-H = 3.86 and IFH = 2.07). These results indicated that the MIPs adsorbs proto-H and proto-PH in lower amounts but with higher specificity than PH and H. In addition, the IF value of MIP IA-AA towards Proto-H in this work was much higher than that reported for the MIPs prepared by surface molecular imprinting techniques (meaning 3.86 compared to 2.88 [24] and 3.07 [25])…”

“…The results pointed out slightly high adsorption capacities (Q=18.28 mg/g) for H and high imprinting factors, near 8. Further on, Pei et al [25] have explored the possibility of using two types of click reactions (azide-alkyne and thiol-yne) to synthesize molecularly imprinted nanospheres with hypericin as the template (MIP-NSHs). In this case, the adsorption capacity of the MIP-NSHs remained high, indicating good stability but the imprinting factors towards H were lower.…”

“…Nevertheless, very few studies were found on the use of MIPs for the separation of the biosynthetic precursors, i.e. proto-hypericin and proto-pseudohypericin [24,25].…”

Molecularly Imprinted Polymer Pearls Obtained by Phase Inversion for the Selective Recognition of Hypericin

“…To this day, few reports on hypericin-MIPs have been published in the literature. For instance, Pei et al prepared molecularly imprinted nanospheres, via click reactions (azide-alkyne and thiol-yne) and surface imprinting techniques, using core-shell magnetic MIP [21,22].…”