Detection of folate binding protein with enhanced sensitivity using a functionalized quartz crystal microbalance sensor
Detection of folate binding protein with enhanced sensitivity using a functionalized quartz crystal microbalance sensor
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DOI：
10.1021/ac060324r
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发表时间：
2006-07-15
影响因子：
7.4
通讯作者：
Savran, Cagri
中科院分区：
文献类型：
--
作者：
Henne, Walter A.;Doorneweerd, Derek D.;Savran, Cagri
本文介绍了一种用于叶酸结合蛋白(FBP)检测的石英晶体微天平生物传感器的研制。利用简单的叶酸-牛血清白蛋白偶联物吸附在镀金的石英传感器上，获得了30 nm的检测下限。在叶酸过量100倍的情况下，FBP与传感器表面的结合可以被高达1mU M的浓度阻断，这表明叶酸-FBP相互作用的专一性，并且不存在与功能化表面的非特异性结合。此外，在血清存在的情况下可以实现捕获，从而使该分析适合于对体液的分析。基于抗FBP抗体和蛋白A包被的金纳米球夹心法的进一步信号增强，将检测下限扩展到50 PM(类似于3个数量级的改进)。鉴于FBP在某些恶性肿瘤和炎症性疾病中的过度表达，我们期待这里描述的方法学有助于检测FBP作为一种可能的疾病诊断生物标记物。
In this report, we describe the development of a quartz crystal microbalance biosensor for detection of folate binding protein (FBP). Using a simple folate-BSA conjugate adsorbed onto a Au-coated quartz sensor, a detection limit of 30 nM was achieved. Binding of FBP to the sensor surface could be blocked at concentrations as high as 1 mu M with a 100-fold excess of folic acid, indicating the specificity of the folate-FBP interaction and the absence of nonspecific binding to the functionalized surface. Moreover, capture could be achieved in the presence of blood serum, making the assay amenable to the analysis of bodily fluids. Further signal enhancement based on an anti-FBP antibody and protein-A-coated gold nanosphere sandwich assay extended the detection limit to 50 pM ( similar to 3 orders-of-magnitude improvement). Given the overexpression of FBP in certain malignancies and inflammatory disorders, we expect the methodology described here to be useful to detect FBP as a possible biomarker for disease diagnosis.