Byzova Nadezhda A, Zherdev Anatoly V, Khlebtsov Boris N, Burov Andrey M, Khlebtsov Nikolai G, Dzantiev Boris B
A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow 119071, Russia.
Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov 410049, Russia.
Sensors (Basel). 2020 Jun 26;20(12):3608. doi: 10.3390/s20123608.
The use of lateral flow immunoassays (LFIAs) for rapid on-site testing is restricted by their relatively high limit of detection (LoD). One possible way to decrease the LoD is to optimize nanoparticle properties that are used as labels. We compare two types of Au nanoparticles: usual quasispherical gold nanoparticles (C-GNPs), obtained by the Turkevich-Frens method, and superspherical gold nanoparticles (S-GNPs), obtained by a progressive overgrowth technique. Average diameters were 18.6-47.5 nm for C-GNPs and 20.2-90.4 nm for S-GNPs. Cardiomarker troponin I was considered as the target analyte. Adsorption and covalent conjugation with antibodies were tested for both GNP types. For C-GNPs, the minimal LoD was obtained with 33.7 nm nanoparticles, reaching 12.7 ng/mL for covalent immobilization and 9.9 ng/mL for adsorption. The average diameter of S-GNPs varied from 20.2 to 64.5 nm, which resulted in a decrease in LoD for an LFIA of troponin I from 3.4 to 1.2 ng/mL for covalent immobilization and from 2.9 to 2.0 ng/mL for adsorption. Thus, we obtained an 8-fold decrease in LoD (9.9 to 1.2 ng/mL) by using S-GNPs. This effect can be related to more effective antibody immobilization and improved S-GNP optical properties. The obtained results can improve LFIAs for various practically significant analytes.
用于快速现场检测的侧向流动免疫分析（LFIA）受到其相对较高的检测限（LoD）的限制。降低检测限的一种可能方法是优化用作标记的纳米颗粒特性。我们比较了两种类型的金纳米颗粒：通过Turkevich-Frens方法获得的普通准球形金纳米颗粒（C-GNP）和通过渐进式过度生长技术获得的超球形金纳米颗粒（S-GNP）。C-GNP的平均直径为18.6-47.5nm，S-GNP的平均直径为20.2-90.4nm。心肌标志物肌钙蛋白I被视为目标分析物。对两种类型的金纳米颗粒都测试了与抗体的吸附和共价偶联。对于C-GNP，使用33.7nm的纳米颗粒获得了最低检测限，共价固定时达到12.7ng/mL，吸附时达到9.9ng/mL。S-GNP的平均直径在20.2至64.5nm之间变化，这导致肌钙蛋白I的LFIA检测限在共价固定时从3.4ng/mL降至1.2ng/mL，吸附时从2.9ng/mL降至2.0ng/mL。因此，通过使用S-GNP，我们将检测限降低了8倍（从9.9ng/mL降至1.2ng/mL）。这种效果可能与更有效的抗体固定和改善的S-GNP光学特性有关。所获得的结果可以改进针对各种实际重要分析物的LFIA。
