Single-layer exfoliated reduced graphene oxide-antibody Tau sensor for detection in human serum

•Single-layer reduced graphene oxide exfoliated by PTSA was first applied in the determination of Tau-441.•This method has great significance to the early diagnosis of AD.•This method performed excellently on the detection of clinical serum samples of AD.•The sensor exhibited its high sensitivity for Tau-441 detection and reached the detection limit of 75 fM. This study presents a novel electrochemical sensor for detection of Tau-441, an Alzheimer's disease (AD) biomarker protein. The sensor comprised a glassy carbon electrode modified by chemically exfoliated single-layer reduced graphene oxide (rGO) grafted with anti-Tau antibody. Using square wave voltammetry (SWV), the electrochemical sensor yielded a linear response to Tau-441 in the 0.08 pM-80 pM concentration range, with a low detection limit of 75 fM. The sensor has been successfully tested in the detection of Tau-441 of human serum from participants with and without AD, therefore it is shown to be an efficient and effective tool for the early diagnosis of AD.