Department of Chemistry, National Sun Yat-sen University , Kaohsiung 80424, Taiwan.
School of Pharmacy, College of Pharmacy, Kaohsiung Medical University , Kaohsiung 80708, Taiwan.
Anal Chem. 2016 May 17;88(10):5355-62. doi: 10.1021/acs.analchem.6b00668. Epub 2016 Apr 29.
Hydrogen-peroxide (H2O2)-induced growth of small-sized gold nanoparticles (AuNPs) is often implemented for H2O2 sensing and plasmonic immunoassay. In contrast, there is little-to-no information in the literature regarding the application of H2O2-inhibited aggregation of citrate-capped AuNPs. This study discloses that benzene-1,4-diboronic acid (BDBA) was effective in driving the aggregation of citrate-capped AuNPs through an interaction between α-hydroxycarboxylate of citrate and boronic acids of BDBA. The H2O2-mediated oxidation of BDBA resulted in the conversion of boronic acid groups to phenol groups. The oxidized BDBA was incapable of triggering the aggregation of citrate-capped AuNPs. Thus, the presence of H2O2 prohibited BDBA-induced aggregation of citrate-capped AuNPs. The BDBA-induced aggregation of citrate-capped AuNPs can be paired with the glucose oxidase (GOx)-glucose system to design a colorimetric probe for glucose. Moreover, a H2O2·BDBA·AuNP probe was integrated with sandwich immunoassay, biotinylated antibody, and avidin-conjugated GOx for the selective naked-eye detection of rabbit immunoglobulin G (IgG) and human-prostate-specific antigen (PSA). The lowest detectable concentrations of rabbit IgG and human PSA by the naked eye were down to 0.1 and 4 ng/mL, respectively. More importantly, the proposed plasmonic immunoassay allowed the naked-eye quantification of 0-10 ng/mL PSA at an interval of 2 ng/mL in plasma samples.
过氧化氢（H2O2）诱导的小尺寸金纳米粒子（AuNPs）的生长常用于 H2O2 传感和等离子体免疫测定。相比之下，关于柠檬酸封端的 AuNPs 的 H2O2 抑制聚集的应用信息很少。本研究表明，苯-1,4-二硼酸（BDBA）通过柠檬酸的α-羟基羧酸和 BDBA 的硼酸之间的相互作用有效地驱动了柠檬酸封端的 AuNPs 的聚集。BDBA 的 H2O2 介导的氧化导致硼酸基团转化为苯酚基团。氧化的 BDBA 不能引发柠檬酸封端的 AuNPs 的聚集。因此，H2O2 抑制了 BDBA 诱导的柠檬酸封端的 AuNPs 的聚集。BDBA 诱导的柠檬酸封端的 AuNPs 的聚集可以与葡萄糖氧化酶（GOx）-葡萄糖系统配对，设计用于葡萄糖的比色探针。此外，将 H2O2·BDBA·AuNP 探针与夹心免疫测定、生物素化抗体和亲和素缀合的 GOx 集成在一起，用于兔免疫球蛋白 G（IgG）和人前列腺特异性抗原（PSA）的选择性肉眼检测。通过肉眼检测到的兔 IgG 和人 PSA 的最低检测浓度分别低至 0.1 和 4ng/mL。更重要的是，所提出的等离子体免疫测定允许在血浆样品中以 2ng/mL 的间隔肉眼定量 0-10ng/mL 的 PSA。
