Ultrasensitive bioanalytical assays are of great value for early detection of human diseases and pathogens. The sensitivities of immunoassays and DNA probing can be enhanced by multilabeling the biorecognition partner used for affinity-based assays. However, the bioreactivity of biomolecules is affected by a high degree of multilabeling at multiple functional sites. It is proposed that dendritic scaffoldings be used to link multiple signal-generating units to a single site with potentially minimum impact on the bioaffinity. A prototype label, a zeroth-generation dendron, bearing three [Ru(bpy)3]2+ units for electrochemiluminescence (ECL) assays was synthesized and characterized preliminarily by spectroscopic, electrochemical, and ECL methods. No evidence of interaction between the neighboring [Ru(bpy)3]2+ units in the label molecule was found from these characterizations. Both the photoluminescence and ECL of the prototype label have features very similar to those of mononuclear [Ru(bpy)3]2+ compounds. Labeling a model protein with a triad of [Ru(bpy)3]2+ at one NH2 position was demonstrated. The results reported here provide support to applying the proposed multilabeling strategy to affinity-based bioanalytical assays.
超灵敏
生物分析测定在早期检测人类疾病和病原体方面具有重要价值。免疫测定和DNA探针的灵敏度可以通过对用于亲和性测定的
生物识别伙伴进行多重标记来提高。然而,
生物分子的
生物反应性会受到在多个功能位点上进行高程度多重标记的影响。建议使用树枝状支架将多个信号生成单元连接到单一位点上,以尽可能减少对
生物亲和力的影响。合成了一种原型标记,即零代树枝状分子,带有三个[Ru(bpy)3]2+单元,用于电
化学发光(
ECL)测定,并通过光谱、电
化学和
ECL方法进行了初步表征。通过这些表征未发现标记分子中相邻[Ru(bpy)3]2+单元之间有相互作用的证据。原型标记的荧光和
ECL特征与单核[Ru(bpy)3]2+化合物非常相似。还演示了将一个三碱基的[Ru(bpy)3]2+在一个NH2位点标记模型蛋白的过程。这里报告的结果支持将所提议的多重标记策略应用于基于亲和性的
生物分析测定。