†Division of Polymer and Composite Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, No. 1219 Zhongguan West Road, Zhenhai District, Ningbo 315201, China.
‡State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
Langmuir. 2015 May 19;31(19):5537-44. doi: 10.1021/acs.langmuir.5b00592. Epub 2015 May 7.
Gold nanoparticles (AuNPs) labeled lateral-flow test strip immunoassay (LFTS) has been widely used in biomedical, feed/food, and environmental analysis fields. Conventional ILFS assay usually uses spherical AuNPs as labeled probes and shows low detection sensitivity, which further limits its widespread practical application. Unlike spherical AuNP used as labeled probe in conventional ILFS, in our present study, a hierarchical flowerlike AuNP specific probe was designed for LFTS and further used to detect Escherichia coli O157:H7 (E. coli O157:H7). Three types of hierarchical flowerlike AuNPs, such as tipped flowerlike, popcornlike, and large-sized flowerlike AuNPs were synthesized in a one-step method. Compared with other two kinds of Au particles, tipped flowerlike AuNPs probes for LFTS particularly exhibited highly sensitive detection of E. coli O157:H7. The remarkable improvement of detection sensitivity of tipped flowerlike AuNPs probes can be achieved even as low as 10(3) colony-forming units (CFU)/mL by taking advantages of its appropriate size and hierarchical structures, which is superior over the detection performance of conventional LFTS. Using this novel tipped flower AuNPs probes, quantitative detection of E. coli O157:H7 can be obtained partially in a wide concentration range with good repeatability. This hierarchical tipped flower-shaped AuNPs probe for LFTS is promising for the practical applications in widespread analysis fields.
金纳米粒子（AuNPs）标记的侧向流测试条免疫分析（LFTS）已广泛应用于生物医学、饲料/食品和环境分析领域。传统的 ILFS 测定通常使用球形 AuNPs 作为标记探针，检测灵敏度较低，这进一步限制了其广泛的实际应用。与传统 ILFS 中用作标记探针的球形 AuNP 不同，在本研究中，设计了一种分层花状 AuNP 特异性探针用于 LFTS，并进一步用于检测大肠杆菌 O157:H7（E. coli O157:H7）。在一步法中合成了三种类型的分层花状 AuNPs，如尖花状、爆米花状和大尺寸花状 AuNPs。与其他两种 Au 颗粒相比，LFTS 的尖花状 AuNPs 探针具有特别高的灵敏度，可检测到低至 10(3) 个菌落形成单位（CFU）/mL 的大肠杆菌 O157:H7。利用其适当的尺寸和分层结构，尖花状 AuNPs 探针的检测灵敏度得到了显著提高，优于传统 LFTS 的检测性能。使用这种新型的尖花 AuNPs 探针，可以在较宽的浓度范围内进行定量检测，具有良好的重复性。这种用于 LFTS 的分层尖花状 AuNPs 探针有望在广泛的分析领域得到实际应用。
