Preparation method and application of electrochemical sensor for heavy metal ions based on aptamers

The invention relates to a preparation method and application of an electrochemical sensor for heavy metal ions based on aptamers, and belongs to the technical field of analytical chemistry. Based on specific binding of specific bases of the aptamers with the metal ions, the aptamers with different sequences are related, so that the selectivity of the sensor for the metal ions is significantly improved, and the sensor is adapted to detection of mercury and silver in water; for the sensor, the mercury ion analysis detection limit is 0.33 nmol/L, and the linear range is 1-200 nmol/L.