Department of Chemistry and Chemical Engineering, Xinxiang University, Xinxiang 453000, China.
Key Laboratory of Analytical Science for Food Safety and Biology (MOE & Fujian Province), Department of Chemistry, Fuzhou University, Fuzhou 350108, China.
Analyst. 2020 Jun 15;145(12):4164-4172. doi: 10.1039/d0an00417k.
Methods based on prussian blue nanoparticles (PBNPs) have been reported for photothermal immunoassays in analytical nanoscience fields but most suffer from low sensitivity and are not beneficial for routine use. Herein, we design an in situ amplified near-infrared (NIR) photothermal immunoassay for the quantitative screening of neuron-specific enolase (NSE) on a portable thermometer using PBNP-encapsulated nanoliposomes as photosensitive materials. Biotinylated liposomes loaded with numerous prussian blue nanoparticles were synthesized through a typical reverse-phase evaporation method. The photothermal immunoassay was carried out in an anti-NSE capture antibody-coated microplate using the biotinylated anti-NSE secondary antibody. With the sandwiched immunoreaction and the biotin-avidin linkage, the subsequent photothermal measurement of PBNPs released from the liposomes with buffered surfactant including Tween 20 was conducted on a digital thermometer under near-infrared 808 nm laser irradiation, accompanied by the convertion of NIR-light wavelength to heat. Under the optimum conditions, the photothermal immunoassay displayed a wide dynamic concentration range of 0.1-100 ng mL-1 with a low detection limit for NSE of 0.053 ng mL-1. Good reproducibility (RSD ≤ 2.78% for intra-assay; RSD ≤ 4.39% for inter-assay), high selectivity against other biomarkers, and a long-term stability (≥94.9% of the initial signal during six-month storage) were acquired in the photothermal immunoassay. Impressively, the analysis of 7 human serum specimens for target NES via the photothermal immunoassay also gave well-matched results with the referenced human NSE enzyme-linked immunosorbent assay.
方法基于普鲁士蓝纳米粒子 (PBNPs) 已被报道用于分析纳米科学领域的光热免疫分析，但大多数方法灵敏度低，不利于常规使用。在此，我们设计了一种基于普鲁士蓝纳米粒子包封的纳米脂质体作为光敏材料的原位放大近红外 (NIR) 光热免疫分析，用于在便携式温度计上定量筛选神经元特异性烯醇化酶 (NSE)。通过典型的反相蒸发法合成了负载大量普鲁士蓝纳米粒子的生物素化脂质体。光热免疫分析在抗 NSE 捕获抗体包被的微孔板中进行，使用生物素化抗 NSE 二级抗体。通过夹心免疫反应和生物素-亲和素连接，随后在近红外 808nm 激光照射下，对缓冲表面活性剂（包括吐温 20）中从脂质体释放的 PBNPs 进行光热测量，同时将近红外光波长转换为热。在最佳条件下，光热免疫分析显示出 0.1-100ng mL-1 的宽动态浓度范围，NSE 的检测限低至 0.053ng mL-1。该光热免疫分析具有良好的重现性（批内 RSD≤2.78%；批间 RSD≤4.39%）、高选择性（针对其他生物标志物）和长期稳定性（≥94.9%的初始信号在六个月的储存期间）。令人印象深刻的是，通过光热免疫分析对 7 个人血清标本进行目标 NES 的分析也与参考的人类 NSE 酶联免疫吸附测定法给出了匹配良好的结果。
