The invention discloses a method for detecting the concentration of 
human epidermal growth factor receptor-2 (HER-2). The method comprises the following steps: 
grinding, cleaning and 
drying gold electrodes; inserting the gold electrodes into a polypeptide solution for carrying out self-
assembly, and then closing the gold electrodes with mercapto 
hexanol; respectively dripping HER-2 with different concentrations onto the surfaces of the gold electrodes for carrying out reactions, and then enabling the gold electrodes to react with an 
aptamer; dripping 
molybdate onto the surfaces of the gold electrodes for carrying out reactions to obtain a plurality of to-be-detected gold electrodes; respectively measuring the gold electrodes by using a 
square wave voltammetry to obtain a plurality of 
square wave voltammetric curves, and making a 
standard curve according to peak currents in all the curves and the corresponding concentrations of the HER-2; dripping the HER-2 to be detected onto the surface of the gold 
electrode assembled with polypeptide for carrying out a reaction, then enabling the gold 
electrode to react with the 
aptamer, dripping 
molybdate onto the surface of the gold 
electrode, measuring by using the 
square wave voltammetry to obtain a square wave voltammetric curve, and contrasting the 
peak current with the 
standard curve to obtain the concentration of the HER-2. The detection method is convenient and fast, good in selectivity, high in sensitivity and wide in detection range.