Department of Biotechnology, University of Turku, Tykistökatu 6A, FI-20520 Turku, Finland.
Anal Chem. 2012 Oct 16;84(20):8628-34. doi: 10.1021/ac301719p. Epub 2012 Oct 2.
A quantitative multianalyte immunoassay utilizing luminescent upconverting single-crystal nanoparticles as reporters on an antibody array-in-well platform was demonstrated. Upconverting nanoparticles are inorganic rare earth doped materials that have the unique feature of converting low energy infrared radiation into higher energy visible light. Autofluorescence, commonly limiting the sensitivity of fluorescence-based assays, can be completely eliminated with photon upconversion technology because the phenomenon does not occur in biological materials. Biotinylated antibodies for three analytes (prostate specific antigen, thyroid stimulating hormone, and luteinizing hormone) were printed in an array format onto the bottom of streptavidin-coated microtiter wells. Analyte dilutions were added to the wells, and the analytes were detected with antibody-coated upconverting nanoparticles. Binding of the upconverting nanoparticles was imaged with an anti-Stokes photoluminescence microwell imager, and the standard curves for each analyte were quantified from the selected spot areas of the images. Single analyte and reference assays were also carried out to compare with the results of the multianalyte assay. Multiplexing did not have an effect on the assay performance. This study demonstrates the feasibility of upconverting single-crystal nanoparticles for imaging-based detection of quantitative multianalyte assays.
一种利用上转换单晶纳米粒子作为抗体阵列-孔板平台上报告物的定量多分析物免疫分析方法得到了证实。上转换纳米粒子是无机稀土掺杂材料，具有将低能量红外辐射转换为高能量可见光的独特特性。自荧光通常限制了基于荧光的分析的灵敏度，但由于该现象不会在生物材料中发生，因此可以通过光子上转换技术完全消除。将三种分析物（前列腺特异性抗原、促甲状腺激素和黄体生成素）的生物素化抗体以阵列格式打印到底部包被链霉亲和素的微孔板上。将分析物稀释液加入孔中，并用抗体包被的上转换纳米粒子检测分析物。上转换纳米粒子的结合通过反斯托克斯光致荧光微孔板成像仪进行成像，并从图像的选定斑点区域定量分析每个分析物的标准曲线。还进行了单分析物和参考分析，以与多分析物分析的结果进行比较。多重分析不会影响分析性能。本研究证明了上转换单晶纳米粒子在基于成像的定量多分析物分析中的可行性。
