AbstractThe authors describe a method for electrochemical determination of the breast cancer biomarker α-lactalbumin (α-LA) using disposable screen-printed carbon electrodes (SPCEs). Lysozyme-conjugated Fe3O4 nanoparticles (Lys-Fe3O4NPs) were used to capture α-LA on the surface of the SPCEs which then is trapped in an immunosandwich using secondary antibodies labeled with ferrocene-modified gold nanoparticles. The amperometric response of ferrocene (recorded at +0.1 V vs. silver pseudo-reference electrode) as well as the electrocatalytic activity of gold nanoparticles on the hydrogen evolution reaction (recorded at −1.0 V Vs Ag pseudo-reference electrode) was exploited to sense α-LA. A sensitive voltammetric response is observed, with (a) a sensitivity of 0.8789 μA·nM−1.cm−2, (b) a detection limit (LOD, at S/N = 3) as low as 0.07 ng·mL−1, and (c) linear response in the 0.75 to 630 ng mL−1 α-LA concentration range. The assay is selective and reproducible, and the SPCEs have good storage stability. The SPCEs were applied (a) to the analysis of (spiked) maternal milk, (b) of spiked serum from healthy and pregnant persons, and (c) of serum of patients suffering from breast cancer. Graphical abstractSchematic presentation of a sensitive electrochemical immunoassay platform based on ferrocene modified gold nanoparticles and lysozyme modified magnetic beads for the determination of alpha lactalbumin in human sera and breast milk by the amperometric response of ferrocene and hydrogen evolution reaction.

中文翻译：

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基于二茂铁修饰的金纳米粒子和溶菌酶修饰的磁珠的乳清蛋白的电化学免疫测定

摘要作者描述了一种使用一次性丝网印刷碳电极 (SPCE) 电化学测定乳腺癌生物标志物 α-乳清蛋白 (α-LA) 的方法。溶菌酶偶联的 Fe3O4 纳米粒子 (Lys-Fe3O4NPs) 用于捕获 SPCE 表面上的 α-LA，然后使用用二茂铁修饰的金纳米粒子标记的二抗将其捕获在免疫夹心中。二茂铁的电流响应（记录在 +0.1 V vs. 银伪参比电极）以及金纳米粒子对析氢反应的电催化活性（记录在 -1.0 V Vs Ag 伪参比电极）被用来检测α-LA。观察到灵敏的伏安响应，(a) 灵敏度为 0.8789 μA·nM−1.cm−2，(b) 检测限（LOD，S/N = 3）低至 0.07 ng·mL−1 , (c) 0.75 至 630 ng mL-1 α-LA 浓度范围内的线性响应。该测定具有选择性和重现性，并且 SPCE 具有良好的储存稳定性。SPCE 被应用于 (a) 分析（加标的）母乳，(b) 来自健康和孕妇的加标血清，以及 (c) 患有乳腺癌的患者的血清。图形摘要基于二茂铁修饰的金纳米粒子和溶菌酶修饰的磁珠的灵敏电化学免疫测定平台的示意图，用于通过二茂铁的安培响应和析氢反应测定人血清和母乳中的 α 乳清蛋白。SPCE 用于 (a) 分析（加标的）母乳，(b) 来自健康和孕妇的加标血清，以及 (c) 患有乳腺癌的患者的血清。图形摘要基于二茂铁修饰的金纳米粒子和溶菌酶修饰的磁珠的灵敏电化学免疫测定平台的示意图，用于通过二茂铁的安培响应和析氢反应测定人血清和母乳中的 α 乳清蛋白。SPCE 被应用于 (a) 分析（加标的）母乳，(b) 来自健康和孕妇的加标血清，以及 (c) 患有乳腺癌的患者的血清。图形摘要基于二茂铁修饰的金纳米粒子和溶菌酶修饰的磁珠的灵敏电化学免疫测定平台的示意图，用于通过二茂铁的安培响应和析氢反应测定人血清和母乳中的 α 乳清蛋白。