Department of Agro-Environmental Sciences, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Department of Agro-Environmental Sciences, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Colloids Surf B Biointerfaces. 2019 Jun 1;178:74-79. doi: 10.1016/j.colsurfb.2019.02.051. Epub 2019 Feb 27.
Monodisperse gold nanoparticles (GNPs) were synthesized in a water-in-oil emulsion system (reverse micelles) composed of 80% N-methylmorpholine N-oxide (NMMO)/20% HO and dodecane, stabilized with an anionic surfactant: bis(2-ethylhexyl)sulfosuccinate sodium salt. Cellooligomers with a degree of polymerization of 6 or 15 (βGlc6 or βGlc15, respectively), which were labeled at each reducing end group with thiosemicarbazide (TSC) and dissolved in the aqueous NMMO phase, were successfully conjugated to the surfaces of GNPs in situ during spontaneous NMMO-mediated gold reduction. As-synthesized βGlc6-GNPs and βGlc15-GNPs had average diameters of 11.3 ± 2.1 and 10.5 ± 0.7 nm, respectively, while their surface sugar densities were 0.21 and 0.51 chains nm, respectively. Concanavalin A (ConA), a lectin that recognizes non-reducing end groups of glucose residues, aggregated with βGlc15-GNPs with higher sensitivity than it did with βGlc6-GNPs, possibly as a result of the sugar density on the GNP surfaces. The aggregates were rapidly re-suspended by adding methyl-β-d-glucopyranoside as a binding inhibitor. Other lectins and proteins showed no interaction with βGlc-GNPs. Therefore, clustering of glucose non-reducing ends on the GNP surfaces via strong intermolecular association of cellooligomers, possibly led to high affinity for ConA. This facile synthesis route to structural carbohydrate-decorated GNPs has potential applications in carbohydrate-nanometal conjugate nano-biosensor development.
单分散金纳米粒子 (GNPs) 在由 80% N-甲基吗啉-N-氧化物 (NMMO)/20% HO 和十二烷组成的油包水乳状液系统 (反胶束) 中合成，该系统由阴离子表面活性剂稳定：双(2-乙基己基)磺基琥珀酸钠盐。聚合度分别为 6 或 15 的纤维素低聚物 (βGlc6 或 βGlc15)，其每个还原端基团都用硫代卡巴肼 (TSC) 标记，并溶解在水相的 NMMO 中，在自发的 NMMO 介导的金还原过程中成功地原位接枝到 GNPs 表面。合成的βGlc6-GNPs 和βGlc15-GNPs 的平均直径分别为 11.3±2.1 和 10.5±0.7nm，而其表面糖密度分别为 0.21 和 0.51 链 nm。凝集素 ConA 可以识别葡萄糖残基的非还原端，与βGlc15-GNPs 的聚集比与βGlc6-GNPs 的聚集更敏感，这可能是由于 GNPs 表面的糖密度所致。通过添加甲基-β-D-吡喃葡萄糖苷作为结合抑制剂，可迅速将聚集物重新悬浮。其他凝集素和蛋白质与βGlc-GNPs 没有相互作用。因此，通过纤维素低聚物的强分子间缔合在 GNPs 表面上聚集葡萄糖非还原端，可能导致对 ConA 的高亲和力。这种简便的合成路线可用于制备结构碳水化合物修饰的 GNPs，在碳水化合物-纳米金属缀合物纳米生物传感器的开发中具有潜在的应用前景。
