College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, PR China.
Petrochina Urumqi Petrochemical Quality Inspection Center, Urumqi, 830019, PR China.
Mikrochim Acta. 2024 Oct 9;191(11):657. doi: 10.1007/s00604-024-06697-3.
With SARS-CoV-2 N protein as a model target, a signal-enhanced LFIA based on Au@Pt nanoparticles (NPs) as labels is proposed. This Au@Pt NPs combined the distinguished localized surface plasma resonance (LSPR) effect of Au NPs and the ultrahigh peroxidase-like catalytic activity of Pt NPs. Au@Pt NPs could trigger substrate chromogenic reaction, generating a color signal orders of magnitude darker than their intrinsic color. In the detection, after the coloration of the strips, 3,3',5,5'-tetramethylbenzidine (TMB) and HO were added, and a dark blue chelate (OxTMB) was produced soon, enhancing the band color significantly. After the signal amplification, the naked-eye detection limit for N protein reached 40 pg/mL. The detection sensitivity enhanced more than 1000 times than that without signal amplification. Compared with mainstream LFIA requiring complex readout instruments, the Au@Pt-based LFIA achieved a comparable sensitivity using naked eyes detection. This point is crucial, especially for unprofessional users or low-resource areas. Hence, this signal-enhanced LFIA may serve as a sensitive, cost-effective, and user-friendly detection method. It can shorten the testing window period and help identify early infections.
以 SARS-CoV-2 N 蛋白为模型靶标，提出了一种基于金@铂纳米粒子（Au@Pt NPs）作为标记物的信号增强 LFIA。该 Au@Pt NPs 结合了 Au NPs 独特的局域表面等离子体共振（LSPR）效应和 Pt NPs 的超高过氧化物酶样催化活性。Au@Pt NPs 可以引发底物显色反应，产生比其固有颜色暗几个数量级的颜色信号。在检测过程中，条带显色后，加入 3,3',5,5'-四甲基联苯胺（TMB）和 HO，很快就会产生深蓝色螯合物（OxTMB），显著增强了条带颜色。经过信号放大后，N 蛋白的肉眼检测限达到 40 pg/mL。检测灵敏度比没有信号放大时提高了 1000 多倍。与需要复杂读出仪器的主流 LFIA 相比，基于 Au@Pt 的 LFIA 仅通过肉眼检测即可达到相当的灵敏度。这一点至关重要，尤其是对于非专业用户或资源匮乏地区。因此，这种信号增强 LFIA 可能成为一种灵敏、经济高效且用户友好的检测方法。它可以缩短检测窗口期，帮助识别早期感染。
