Highly sensitive electrochemical determination of neutrophil gelatinase-associated lipocalin for acute kidney injury

► A novel and simple label-free electrochemical immunosensor for the ultrasensitive detection of NGAL is developed. ► The LA2/AuNPs immunoelectrode is found to detect NGAL in the concentration range of 50-250 ng mL−1 with a low detection limit of 1 ng mL−1 (280 pM; based on S/N = 3). ► The developed immunosensor has been proved by the satisfactory results of the usage to determine NGAL in both blood serum and urine samples.