Wang Yanyan, Liu Bin
Department of Chemical and Biomolecular Engineering, 4 Engineering Drive 4, National University of Singapore, 117567, Singapore.
Langmuir. 2009 Nov 3;25(21):12787-93. doi: 10.1021/la901703p.
The detection of disease-related proteins in complex biological media demands sensitive, reliable, and low-cost sensing methods. We present here an assay with aptamer-functionalized silica nanoparticles (NPs) as the sensory platform for thrombin detection in blood serum. As a result of specific protein/aptamer interaction, the presence of thrombin induces the primary aptamer-functionalized NPs to form a sandwich structure with fluorescein-labeled secondary aptamer and results in fluorescent NPs. A conjugated polyelectrolyte is further added to the NP solution to amplify the fluorescent signal. The assay shows high specificity for thrombin detection in serum. In addition, a detection limit of 1.06 nM is obtained, which is significantly improved as compared to that for many fluorescence-based thrombin detection assays. Using lysozyme as a second example, the NP-based detection strategy is shown to be generic and could be readily applicable to the detection of other proteins in practical samples.
在复杂生物介质中检测疾病相关蛋白质需要灵敏、可靠且低成本的传感方法。我们在此展示一种以适配体功能化二氧化硅纳米颗粒（NPs）作为传感平台用于检测血清中凝血酶的分析方法。由于特异性蛋白质/适配体相互作用，凝血酶的存在会诱导初级适配体功能化的纳米颗粒与荧光素标记的二级适配体形成夹心结构，从而产生荧光纳米颗粒。再向纳米颗粒溶液中进一步添加共轭聚电解质以放大荧光信号。该分析方法对血清中凝血酶的检测具有高特异性。此外，获得了1.06 nM的检测限，与许多基于荧光的凝血酶检测分析方法相比有显著提高。以溶菌酶作为第二个例子，基于纳米颗粒的检测策略显示具有通用性，并且可以很容易地应用于实际样品中其他蛋白质的检测。
