Institute for Global Food Security, School of Biological Sciences, Queen's University, 19 Chlorine Gardens, Belfast BT9 5DL, UK.
CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Jordi Girona 18-26, 08034 Barcelona, Spain; Nanobiotechnology for Diagnostics (Nb4D), Institute for Advanced Chemistry of Catalonia (IQAC) of the Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 May 5;252:119473. doi: 10.1016/j.saa.2021.119473. Epub 2021 Jan 16.
An immunoassay was developed that utilized plasmonic coupling between immobilised gold nanorods and colloid gold nanospheres to detect the marine toxin domoic acid (DA). The aspect ratio of the nanorods was optimised and the effects of variation in acidity, silver to gold ratio, cetyltrimethylammonium bromide (CTAB) concentration and seed addition in the growth solution on the yield, size variance and LSPR peak position was investigated. Excellent nanorods (size variation < 15%; aspect ratio 3.5-5; yield 0.26-0.35 nM mL) were obtained for the LSPR range 785-867 nm using strong acidic conditions (12 µl HCl (37%)), silver to gold ratio of 1:5, 0.05-0.1 M CTAB and 20-30 µl seed addition to 10 mL of growth solution. One set of nanorods (54.9 X 15.7 nm; LSPR 785 nm) were immobilised onto a silica support and bio-functionalised with DA hapten. Colloid nanospheres (15 nm; LSPR 519 nm) were bio-functionalised with an anti-domoic-acid monoclonal antibody. The functionalised nanoparticles were used to detect DA by plasmon coupling by quantifying the average LSPR shift of individual plasmon couples with hyperspectral imaging or quantifying the pixels count caused by the particle aggregation visible under darkfield microscopy. The first method led to a LSPR blue-shift of 55 nm caused by the immunoreaction. The second, simpler method, enabled very clear qualitative detection (p < 0.0005) of domoic acid when 10 µM domoic acid was added. Both methods show potential though the novelty and simplicity of the second platform allowing rapid (30 min) detection with high-throughput possibilities using a simple set-up is of most interest.
开发了一种免疫分析方法，利用固定化金纳米棒与胶体金纳米球之间的等离子体耦合来检测海洋毒素软骨藻酸 (DA)。优化了纳米棒的纵横比，并研究了酸度、银与金的比例、十六烷基三甲基溴化铵 (CTAB) 浓度和种子在生长溶液中的添加对产率、尺寸变化和 LSPR 峰位置的影响。在酸性条件下（12 μl HCl (37%)），银与金的比例为 1:5，CTAB 浓度为 0.05-0.1 M，生长溶液中添加 20-30 μl 种子，获得了 LSPR 范围为 785-867 nm 的优异纳米棒（尺寸变化 <15%；纵横比 3.5-5；产率 0.26-0.35 nM mL）。将一组纳米棒（54.9×15.7 nm；LSPR 785 nm）固定在二氧化硅载体上，并与 DA 半抗原生物功能化。胶体纳米球（15 nm；LSPR 519 nm）与抗软骨藻酸单克隆抗体生物功能化。通过超光谱成像定量单个等离子体偶合的平均 LSPR 位移，或通过量化暗场显微镜下可见的颗粒聚集引起的像素计数，使用功能化的纳米粒子通过等离子体偶合来检测 DA。第一种方法导致免疫反应引起的 LSPR 蓝移约 55nm。第二种更简单的方法可以非常清晰地定性检测（p <0.0005）当添加 10 μM 软骨藻酸时。两种方法都具有潜力，尽管第二个平台的新颖性和简单性允许使用简单的设置快速（~30 分钟）进行高通量检测，但最感兴趣的是。
