Ultra-sensitive and label-free neutrophil gelatinase-associated lipocalin electrochemical sensor using gold nanoparticles decorated 3D Graphene foam towards acute kidney injury detection

Abstract

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.