Department of Chemistry, Kyungpook National University, Daegu, 702-701, South Korea.
Biomed Microdevices. 2013 Feb;15(1):195-202. doi: 10.1007/s10544-012-9716-x.
A rapid and sensitive chemiluminescence (CL) system coupled with a microfluidic chip has been presented to determine vitamin B12 (VB12) based on the reaction of luminol and silver nitrate (AgNO(3)) in the presence of gold nanoparticles (AuNPs). A microfluidic chip was fabricated by a soft-lithographic procedure using polydimethyl siloxane (PDMS) having four inlets and one outlet with a 200 μm wide, 250 μm deep, and 100 mm long microchannel. Ag(+) was used as a chemiluminogenic oxidant in this CL reaction which oxidized luminol to produce strong CL signal in the presence of AuNPs. Luminol reacted with AgNO(3) under the catalysis of AuNPs to produce luminol radicals which reacted with dissolved oxygen and emitted CL light. The proposed CL system was applied to determine the amount of VB12 in VB12 tablets and multivitamin. Under the optimum conditions, the CL intensity of the system was increased with the concentration of VB12 in the range of 0.25-100 ng mL(-1) with the correlation coefficient of 0.9982. The limit of detection was found to be 0.04 ng mL(-1) with the relative standard deviation of 1.56 % for five replicate determinations of 25 ng mL(-1) of VB12. The CL reaction mechanism was demonstrated by UV-visible spectra and CL emission spectra.
一种基于金纳米粒子（AuNPs）存在下鲁米诺和硝酸银（AgNO3）反应的快速灵敏化学发光（CL）系统与微流控芯片相结合，用于测定维生素 B12（VB12）。微流控芯片通过使用具有四个入口和一个出口的聚二甲基硅氧烷（PDMS）通过软光刻工艺制造，具有 200 μm 宽、250 μm 深和 100 mm 长的微通道。在这个 CL 反应中，Ag+被用作化学发光氧化剂，它在 AuNPs 的存在下将鲁米诺氧化为产生强 CL 信号。鲁米诺在 AuNPs 的催化下与 AgNO3 反应生成鲁米诺自由基，鲁米诺自由基与溶解氧反应并发出 CL 光。所提出的 CL 系统被应用于测定 VB12 片剂和多种维生素中的 VB12 含量。在最佳条件下，随着 VB12 浓度在 0.25-100 ng mL(-1)范围内的增加，系统的 CL 强度增加，相关系数为 0.9982。对于 25 ng mL(-1) VB12 的五次重复测定，检测限为 0.04 ng mL(-1)，相对标准偏差为 1.56%。通过紫外可见光谱和 CL 发射光谱证明了 CL 反应机制。
