Molecular detection unit, chip and preparation method

A method for preparing a molecular detection chip, comprising:

• preparing a substrate, and forming a sensing electrode of each molecular detection unit in a molecular detection chip on the substrate respectively;
• the sensing electrode is used to detect a voltage applied to a side of the single-hole liquid storage cavity;
• forming a first structural layer on the substrate, and forming a corresponding single-hole liquid storage cavity, liquid resistance flow channel and buffer flow channel for each molecular detection unit in the molecular detection chip in the first structural layer, and the buffer flow channels of a plurality of molecular detection units in each row of molecular detection units being communicated with each other as a common buffer flow channel;
• for a molecular detection array, forming a second structural layer on the first structural layer, sealing the common buffer flow channel and the buffer flow channel of each molecular detection unit, and forming a sample flow channel for each molecular detection unit in the second structural layer, and the sample flow channels of a plurality of molecular detection units in each row of molecular detection units being communicated with each other as a common sample flow channel;
• forming a third structural layer on the second structural layer, and forming sample access holes communicated with two ends of the common sample flow channel and forming buffer access holes communicated with two ends of the common buffer flow channel for the molecular detection array;
• and
• forming an upper cover on the third structural layer, and forming a first interface and a second interface on the upper cover for the molecular detection array;
• wherein, the first interface is located above the sample access holes, and the second interface is located above the buffer access holes.