AbstractAn enzyme-free electrochemical immunoassay is described for the neutrophil gelatinase-associated lipocalin (NGAL; a biomarker of kidney disease). Prussian Blue (PB) nanoparticles with redox activity were deposited on graphitic C3N4 nanosheets (g-C3N4) by in-situ reduction. A screen printed electrode (SPCE) was modified with antibody against NGAL, and the PB-g-C3N4 nanohybrid was used as the signal-generating tag for the secondary antibody against NGAL. Upon addition of target NGAL and of secondary antibody, a sandwich is formed on the SPCE. At an applied potential of typically 0.13 V (vs. Ag/AgCl), a well-defined voltammetric peak is observed that results from the presence of PB on the secondary antibody. Under optimal conditions, the peak current increases linearly in the 0.01 to 10 ng·mL−1 NGAL concentration range, and the detection limit is 2.8 pg·mL−1. An average precision of <12% was accomplished in the batch-to-batch mode. Other disease-related biomarkers do not interfere. The accuracy and inter-laboratory validation of this method were evaluated for target NGAL detection in spiked human serum by using a commercial ELISA. The results obtained by the two methods are in good accordance. Graphical abstractAn enzyme-free electrochemical immunoassay was used for detection of neutrophil gelatinase-associated lipocalin by Prussian blut/graphitic-C3N4 nanohybrids as the signal-generation tags.

中文翻译：

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由普鲁士蓝和石墨 C3N4 纳米片组成的纳米杂化物作为中性粒细胞明胶酶相关脂质运载蛋白的无酶电化学免疫测定中的信号生成标签

摘要描述了中性粒细胞明胶酶相关脂质运载蛋白（NGAL；肾脏疾病的生物标志物）的无酶电化学免疫分析。通过原位还原将具有氧化还原活性的普鲁士蓝 (PB) 纳米颗粒沉积在石墨 C3N4 纳米片 (g-C3N4) 上。丝网印刷电极 (SPCE) 用抗 NGAL 的抗体修饰，PB-g-C3N4 纳米杂交体用作抗 NGAL 的二抗的信号生成标签。在添加目标 NGAL 和二抗后，在 SPCE 上形成夹心。在通常为 0.13 V（相对于 Ag/AgCl）的施加电位下，观察到明确定义的伏安峰，这是由于二抗上存在 PB。在最佳条件下，峰值电流在 0.01 至 10 ng·mL−1 NGAL 浓度范围内线性增加，检出限为2.8 pg·mL-1。在批次间模式下实现了 <12% 的平均精度。其他疾病相关的生物标志物不会干扰。使用商业 ELISA 评估了该方法的准确性和实验室间验证，用于在加标人血清中检测目标 NGAL。两种方法得到的结果吻合良好。图形摘要无酶电化学免疫测定法用于检测中性粒细胞明胶酶相关脂质运载蛋白，由普鲁士 blut/graphitic-C3N4 纳米杂化物作为信号生成标签。使用商业 ELISA 评估了该方法的准确性和实验室间验证，用于在加标人血清中检测目标 NGAL。两种方法得到的结果吻合良好。图形摘要无酶电化学免疫测定法用于检测中性粒细胞明胶酶相关脂质运载蛋白，由普鲁士 blut/graphitic-C3N4 纳米杂化物作为信号生成标签。使用商业 ELISA 评估了该方法的准确性和实验室间验证，用于在加标人血清中检测目标 NGAL。两种方法得到的结果吻合良好。图形摘要无酶电化学免疫测定法用于检测中性粒细胞明胶酶相关脂质运载蛋白，由普鲁士 blut/graphitic-C3N4 纳米杂化物作为信号生成标签。