Institute for Molecular Bioscience, 306 Carmody Road, The University of Queensland, Brisbane, 4072, QLD, Australia.
Institute for Molecular Bioscience, 306 Carmody Road, The University of Queensland, Brisbane, 4072, QLD, Australia; School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, 4072, QLD, Australia.
Anal Chim Acta. 2020 Apr 22;1107:85-91. doi: 10.1016/j.aca.2020.02.007. Epub 2020 Feb 5.
We report a flow-cytometry based method capable of detecting a range of analytes by monitoring the analyte-induced clustering of magnetic and fluorescent nanoparticles with flow cytometry. Using the dengue viral antigen (NS1) as an example, antibodies were conjugated to magnetic and fluorescent nanoparticles in a sandwich immunoassay format. These nanoparticles formed clusters when NS1 was present in a sample and the cluster formation was directly proportional to the concentration of antigen. Simultaneous flow cytometry measurement of cluster size, as detected by the forward scatter channel, combined with fluorescence intensity led to a reduction in the assay background signal, resulting in improved analytical sensitivity. We were able to detect 2.5 ng mL of NS1 in serum samples by quantifying the clusters, a two-log fold improvement in the assay limit of detection over total fluorescence quantification alone.
我们报告了一种基于流式细胞术的方法，通过监测磁珠和荧光珠在流动相中因分析物诱导而产生的聚集，从而实现对多种分析物的检测。我们以登革热病毒抗原（NS1）为例，将抗体以三明治免疫测定的形式偶联到磁珠和荧光珠上。当样本中存在 NS1 时，这些纳米粒子会形成簇，并且簇的形成与抗原的浓度成正比。通过前向散射通道直接检测到的簇大小的同时流式细胞术测量，再结合荧光强度，降低了测定的背景信号，从而提高了分析灵敏度。通过对簇进行定量，我们能够在血清样本中检测到 2.5ng/mL 的 NS1，与单独进行总荧光定量相比，检测限提高了两个数量级。
