The invention discloses a preparation method of a spherical
DNA nano
machine for detecting O6-methylguanine-
DNA methyltransferase (MGMT) and application of the spherical
DNA nano
machine in detection of the expression level of
tumor cells MGMT. The method comprises the following steps: firstly, designing
a DNA walker with MGMT recognition and
signal amplification functions, and fixing the
DNA walker on the surface of a gold nanosphere through sulfydryl modification to construct a spherical DNA nanomachine; when the MGMT interacts with
a DNA Walker chain, a methylated basic group G on DNA
enzyme can be repaired, so that the activity of the DNA
enzyme is recovered, an
enzyme digestion reaction is initiated, a Track chain marked with a
fluorophore is broken and released, a
fluorescence signal change is generated, and high-sensitivity detection of the MGMT is realized. The method can effectively detect the MGMT
protein in a low concentration range, and has a good biomedical application prospect.