School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, People's Republic of China.
J Agric Food Chem. 2021 Dec 15;69(49):14751-14760. doi: 10.1021/acs.jafc.1c04309. Epub 2021 Sep 15.
Nanozymes as a cost-effective and robust enzyme mimic have attracted widespread attention in the development of novel analytical methods. Herein, a new nanozyme-enhanced surface-enhanced Raman scattering (SERS) immunoassay platform was successfully developed using a peroxidase-mimicking nanozyme to replace the natural enzymes as a catalytic label of the enzyme-linked immunosorbent assay for the detection of allergy proteins. In this platform, the peroxidase-mimicking nanozymes as a catalytic label could catalyze the oxidation of the Raman-inactive reporter [i.e., leucomalachite green (LMG)] to generate Raman-active malachite green (MG) with HO. Moreover, the produced MG Raman signal was further enhanced by the formed Raman "hot spot" through MG-induced gold nanoparticle aggregation, which could be recorded by a portable Raman spectrometer. On this basis, the established nanozyme-enhanced SERS immunoassay showed improved accuracy, high sensitivity, and good selectivity and was used for accurate quantification of α-lactalbumin (α-LA). With this method, α-LA could be detected with a limit of detection as low as 0.01 ng/mL. Moreover, the method was also verified by performing in food samples and showed satisfactory recoveries and high reliability. This study not only provides insight into the use of a nanozyme to establish new analytical methods but also broadens the applications of nanozymes in a food safety assay.
纳米酶作为一种具有成本效益和稳健的酶模拟物，在新型分析方法的发展中引起了广泛关注。在此，我们成功开发了一种新的纳米酶增强表面增强拉曼散射（SERS）免疫分析平台，该平台使用过氧化物酶模拟纳米酶代替天然酶作为酶联免疫吸附测定的催化标签，用于检测过敏蛋白。在该平台中，过氧化物酶模拟纳米酶作为催化标签可以催化拉曼非活性报告物[即亮绿素（LMG）]的氧化，生成具有 HO 的拉曼活性孔雀石绿（MG）。此外，通过 MG 诱导的金纳米颗粒聚集形成的拉曼“热点”进一步增强了产生的 MG 拉曼信号，可通过便携式拉曼光谱仪记录下来。在此基础上，建立的纳米酶增强 SERS 免疫分析具有更高的准确性、灵敏度和良好的选择性，并用于准确定量α-乳白蛋白（α-LA）。该方法的检测限低至 0.01ng/mL。此外，该方法还通过在食品样品中的验证，表现出令人满意的回收率和高度可靠性。本研究不仅为利用纳米酶建立新的分析方法提供了思路，还拓宽了纳米酶在食品安全检测中的应用。
