Research Institute of Green Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
Graduate School of Integrated Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
Biosens Bioelectron. 2017 Jan 15;87:558-565. doi: 10.1016/j.bios.2016.08.101. Epub 2016 Aug 30.
A hybrid structure of graphene-gold nanoparticles (Grp-Au NPs) was designed as a new nanoprobe for colorimetric immunoassays. This hybrid structure was prepared using chloroauric acid, sodium formate and Grp flakes at room temperature. Au NPs attached strongly onto the Grp surface, and their size was controlled by varying the sodium formate concentration. The Raman intensity of the Grp-Au NP hybrids was significantly enhanced at 1567cm and 2730cm compared with those of pristine Grp because of the electronic interaction between Au NPs and Grp. The Grp-Au NPs with a hybrid structure catalyzed the oxidation of the peroxidase substrate 3,3,5,5-tetramethylbenzidine (TMB) with HO, developing a blue color in aqueous solution. This catalytic activity was utilized to detect norovirus-like particles (NoV-LPs) in human serum. The enhanced colorimetric response was monitored using Ab-conjugated-Grp-Au NPs and found to depend on the NoV-LP concentration, exhibiting a linear response from 100pg/mL to 10μg/mL. The limit of detection (LOD) of this proposed method was 92.7pg/mL, 112 times lower than that of a conventional enzyme-linked immunosorbent assay (ELISA). The sensitivity of this test was also 41 times greater than that of a commercial diagnostic kit. The selectivity of the Grp-Au NPs was tested with other viruses, and no color changes were observed. Therefore, the proposed system will facilitate the utilization of the intrinsic peroxidase-like activity of Grp-Au NPs in medical diagnostics. We believe that the engineered catalytic Grp-Au NP hybrids could find potential applications in the future development of biocatalysts and bioassays.
一种石墨烯-金纳米粒子（Grp-Au NPs）的杂化结构被设计为比色免疫分析的新型纳米探针。该杂化结构是在室温下使用氯金酸、甲酸钠和 Grp 薄片制备的。Au NPs 强烈附着在 Grp 表面上，并且通过改变甲酸钠浓度来控制其尺寸。与原始 Grp 相比，Grp-Au NP 杂化结构的 Raman 强度在 1567cm 和 2730cm 处显著增强，这是由于 Au NPs 和 Grp 之间的电子相互作用。具有杂化结构的 Grp-Au NPs 催化过氧化物酶底物 3,3,5,5-四甲基联苯胺（TMB）与 HO 的氧化，在水溶液中产生蓝色。这种催化活性被用于检测人血清中的诺如病毒样颗粒（NoV-LPs）。使用 Ab 缀合的 Grp-Au NPs 监测增强的比色响应，并发现该响应依赖于 NoV-LP 浓度，从 100pg/mL 到 10μg/mL 呈线性响应。该方法的检测限（LOD）为 92.7pg/mL，比传统的酶联免疫吸附测定（ELISA）低 112 倍。该测试的灵敏度也比商业诊断试剂盒高 41 倍。用其他病毒测试了 Grp-Au NPs 的选择性，没有观察到颜色变化。因此，该系统将有助于在医学诊断中利用 Grp-Au NPs 的固有过氧化物酶样活性。我们相信，工程化的催化 Grp-Au NP 杂化体在未来的生物催化剂和生物测定中可能具有应用潜力。
