Colorimetric and Fluorescent Dual-Mode Immunoassay Based on Plasmon-Enhanced Fluorescence of Polymer Dots for Detection of PSA in Whole Blood
Colorimetric and Fluorescent Dual-Mode Immunoassay Based on Plasmon-Enhanced Fluorescence of Polymer Dots for Detection of PSA in Whole Blood
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DOI：
10.1021/acsami.9b00204
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发表时间：
2019-03-13
影响因子：
9.5
通讯作者：
Chan, Yang-Hsiang
中科院分区：
文献类型：
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作者：
You, Pei-Yun;Li, Fang-Chu;Chan, Yang-Hsiang
尽管在过去的几年里，人们已经付出了巨大的努力来开发具有改进的灵敏度的新型荧光免疫层析测试条（ICTS），但是设计具有比色和荧光双峰信号读出的ICTS以用于在临床中快速而准确地检测癌症标志物仍然是一个很大的挑战。科学家们试图通过将荧光染料与金属纳米材料结合来制备双峰报告分子，但它们的荧光很容易被金属纳米材料通过表面能量转移猝灭，使得双重比色和荧光ICTS非常难以实现。与传统的荧光探针相比，半导体聚合物点（Pdot）具有非凡的荧光亮度和容易的表面功能化，非常适合作为双峰信号报告试剂。在这里，我们将高荧光Pdot与强等离子体Au纳米棒集成，以形成具有双重比色和荧光读出能力的Pdot-Au混合纳米复合材料。我们进一步利用这些纳米杂化物在ICTS定性快速筛选（比色法）以及定量准确测定通过利用Au纳米棒上Pdot的等离子体增强荧光，该免疫测定法对PSA具有更好的检测灵敏度1.07 pg/mL，其比常规荧光ICTS的低至少2个数量级。此外，直接检测从人类全血收集的PSA，而无需样品预处理，使得这种基于Pdot的ICTS平台有望用于现场护理点诊断。
Although enormous efforts have been devoted to the development of new types of fluorometric immuno-chromatographic test strip (ICTS) with improved sensitivity over the past years, it still remains a big challenge to design ICTS with colorimetric and fluorescent bimodal signal readout for rapid yet accurate detection of cancer markers in a clinic. Scientists have tried to prepare bimodal reporters by combining fluorescent dyes with metal nanomaterials, but their fluorescence was easily quenched by metal nanomaterials through surface energy transfer, making dual colorimetric and fluorometric ICTS very difficult to be achieved. As compared to conventional fluorescent probes, semiconducting polymer dots (Pdots) exhibit extraordinary fluorescence brightness and facile surface functionalization, which are very suitable to be engineered as bimodal signal reporting reagents. Here, we integrated highly fluorescent Pdots with strongly plasmonic Au nanorods to form Pdot-Au hybrid nanocomposites with dual colorimetric and fluorescent readout abilities. We further utilized these nanohybrids in ICTS for qualitatively fast screening (colorimetry) as well as quantitatively accurate determination (fluorometry) of prostate-specific antigen (PSA) within 10 min. By taking advantage of the plasmon-enhanced fluorescence of Pdots on Au nanorods, this immunoassay possesses much better detection sensitivity of 1.07 pg/mL for PSA, which is at least 2 orders of magnitude lower than that of conventional fluorometric ICTS. Moreover, the direct detection of PSA from human whole blood collected without sample pretreatment makes this Pdot-based ICTS platform promising for on-site point-of-care diagnostics.