Mercuric ion or cysteine detecting electrochemical DNA biosensor and manufacturing method and application thereof

The invention discloses a mercuric ion or cysteine detecting electrochemical DNA biosensor and a manufacturing method and application thereof.The electrochemical DNA biosensor comprises a glassy carbon electrode serving as a working electrode of a three-electrode system; the surface of a reactive end of the glassy carbon electrode is modified by composite membrane composed of auto-doped polyaniline nanofiber, ordered mesoporous carbon and nano-scale gold particles; a DNA capture probe, with the nucleotide sequence SEQ ID NO.1 is assembled on the surface of the composite membrane.The manufacturing method includes steps of modifying auto-doped polyaniline nanofiber and ordered mesoporous carbon, electrodepositing nano-scale gold particles, assembling the DNA capture probe and the like.The mercuric ion or cysteine detecting electrochemical DNA biosensor capable of detecting two different target substances has the advantages of high stability, long service life, high interference resistance capacity, wide detecti