Panferov Vasily, Ivanov Nikita, Zhang Wenjun, Wang Sihan, Liu Juewen
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
A.N. Bach Institute of Biochemistry, Federal Research Centre ″Fundamentals of Biotechnology″, Russian Academy of Sciences, 33 Leninsky Prospect, Moscow 119071, Russia.
ACS Sens. 2025 May 23;10(5):3785-3793. doi: 10.1021/acssensors.5c00990. Epub 2025 May 5.
Lateral flow assays (LFAs) are essential for point-of-care testing. The use of peroxidase-mimicking nanozymes as catalytic labels is an actively developing direction in LFA, primarily focused on enhancing sensitivity. However, endogenous peroxidases, naturally present in various samples, can interfere with nanozyme signal amplification, leading to a high background signal and making visual detection more challenging. The issue of endogenous peroxidases is particularly significant for LFAs as wash-free biosensors. In this study, we showcase the remarkable thermostability of nanozymes in contrast to enzymes, applied to the analytically relevant use of lateral flow assays for the detection of aflatoxin B1. By employing Joule heating in a portable battery-powered device, the test strips were rapidly heated to 75-80 °C after completing the conventional LFA process. This heating caused thermal denaturation of endogenous peroxidases without affecting the Au@Pt nanozymes. As a result, substrate oxidation on the test strip was carried out solely by the Au@Pt nanozymes, which reduced background noise and improved the limit of detection by a factor of 3.5 compared to the assay without heating.
侧向流动分析（LFA）对于即时检测至关重要。使用模拟过氧化物酶的纳米酶作为催化标记物是LFA中一个积极发展的方向，主要致力于提高灵敏度。然而，各种样品中天然存在的内源性过氧化物酶会干扰纳米酶信号放大，导致背景信号过高，使得视觉检测更具挑战性。对于作为免洗生物传感器的LFA而言，内源性过氧化物酶的问题尤为突出。在本研究中，我们展示了与酶相比纳米酶具有显著的热稳定性，并将其应用于侧向流动分析检测黄曲霉毒素B1的相关分析用途。通过在便携式电池供电设备中采用焦耳加热，在完成传统LFA过程后，测试条被迅速加热至75 - 80°C。这种加热使内源性过氧化物酶发生热变性，而不影响Au@Pt纳米酶。结果，测试条上的底物氧化仅由Au@Pt纳米酶进行，与未加热的检测相比，这降低了背景噪声，并将检测限提高了3.5倍。
