In this work, an ultra-sensitive and highly-specific electrochemical immunosensor was developed based on three-dimensional graphene/nickel foam (GF) decorated with gold nanoparticles (AuNPs) for the detection of Neutrophil Gelatinase-Associated Lipocalin (NGAL), a biomarker of Acute Kidney Injury (AKI). A low NGAL limit of detection (LOD) of 42 pg/ml and a linear range (LR) of 0.05–210 ng/ml were achieved. Though several electrode platforms have been proposed, either LOD or LR are limited for each method. Our platform can achieve low LOD while keeping broad LR of sensing. Self-Assembled-Monolayer (SAM) and 11-mercaptoundecanoic acid (11-MUA) were used to assist antibody binding on AuNPs. Electrochemical determination of NGAL were conducted using cyclic voltammetry and chronoamperometry on ferri/ferrocyanide redox measurement. Specificity was tested for NGAL detection against uric acid and creatinine interference. The attained performances might be ascribed to large specific surface area of GF and AuNPs, improved electron transfer from analyte via graphene‑nickel‑gold electric dipole enhancement. The results demonstrated the proposed platform was potential for ultra-sensitive, highly specific, non-invasive and real-time electrochemical detection of NGAL.

在这项工作中，开发了一种基于三维石墨烯/镍泡沫（GF）的超灵敏，高度特异性的电化学免疫传感器，该电极装饰有金纳米颗粒（AuNPs），用于检测中性粒细胞明胶酶相关的脂蛋白（NGAL）（一种生物标志物）急性肾损伤（AKI）。NGAL的检测下限（LOD）为42 pg / ml，线性范围（LR）为0.05–210 ng / ml。尽管已经提出了几种电极平台，但是每种方法都限制了LOD或LR。我们的平台可以实现低LOD，同时保持宽广的LR感测。自组装单分子层（SAM）和11-巯基癸酸（11-MUA）用于协助抗体与AuNPs结合。使用循环伏安法和计时电流法在亚铁/亚铁氰化物氧化还原测量中进行NGAL的电化学测定。测试了针对尿酸和肌酐干扰的NGAL检测的特异性。达到的性能可能归因于GF和AuNPs的大比表面积，通过石墨烯-镍-金电偶极子增强提高了从分析物中的电子转移。结果表明，所提出的平台对于NGAL的超灵敏，高特异性，无创和实时电化学检测具有潜力。