Lai Xiaocui, Zhang Ganggang, Zeng Lifeng, Xiao Xiaoyue, Peng Juan, Guo Ping, Zhang Wei, Lai Weihua
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
Institute of Microbiology, Jiangxi Academy of Sciences, Nanchang 330096, China.
ACS Appl Mater Interfaces. 2021 Jan 13;13(1):1413-1423. doi: 10.1021/acsami.0c17957. Epub 2020 Dec 21.
Immunochromatographic assay (ICA) is widely applied in various fields. However, severe matrix interference and weak signal output present major challenges in achieving accurate and ultrasensitive detection in ICA. Here, a polydopamine (PDA)-mediated magnetic bimetallic nanozyme (FeO@PDA@Pd/Pt) with peroxidase-like activity was synthesized and used as a probe in ICA. The magnetic property of FeO@PDA@Pd/Pt enabled effective magnetic enrichment of targets, thereby reducing the matrix interference in the sample. PDA coating on the magnetic bimetallic nanozyme was employed as a mediator and a stabilizer. It improved the catalytic ability and stability of the magnetic bimetallic nanozyme by providing more coordination sites for Pd/Pt growth and functional groups (-NH and -OH). In addition, the Pd/Pt bimetallic synergistic effect could further enhance the catalytic ability of the nanozyme. A method was developed by integrating FeO, PDA, and Pd/Pt into FeO@PDA@Pd/Pt as a probe in ICA. With the proposed method, human chorionic gonadotropin and O157:H7 were successfully detected to be as low as 0.0094 mIU/mL in human blood serum and 9 × 10 CFU/mL in the milk sample, respectively. This method may be readily adapted for accurate and ultrasensitive detection of other biomolecules in various fields.
免疫层析分析（ICA）在各个领域都有广泛应用。然而，严重的基质干扰和微弱的信号输出是免疫层析分析实现准确和超灵敏检测的主要挑战。在此，合成了一种具有过氧化物酶样活性的聚多巴胺（PDA）介导的磁性双金属纳米酶（FeO@PDA@Pd/Pt），并将其用作免疫层析分析中的探针。FeO@PDA@Pd/Pt的磁性能够有效富集目标物，从而减少样品中的基质干扰。磁性双金属纳米酶上的PDA涂层用作介质和稳定剂。它通过为Pd/Pt生长提供更多配位位点和官能团（-NH和-OH），提高了磁性双金属纳米酶的催化能力和稳定性。此外，Pd/Pt双金属协同效应可进一步增强纳米酶的催化能力。通过将FeO、PDA和Pd/Pt整合到FeO@PDA@Pd/Pt中作为免疫层析分析的探针，开发了一种方法。利用该方法，在人血清中成功检测到低至0.0094 mIU/mL的人绒毛膜促性腺激素，在牛奶样品中成功检测到低至9×10 CFU/mL的O157:H7。该方法可能易于适用于各个领域中其他生物分子的准确和超灵敏检测。
