An α fetoprotein (AFP) antibody gene probe was constructed using chlorophyll molecule as a coupler between protein and dsDNA. The preliminary study on the detection of AFP using this novel probe was performed by immuno PCR, and the results indicated that the sensitivity of the gene probe by immuno PCR is 10 4-10 5 times higher compared with ELISA. The construction of immuno PCR gene probe in this way not only completely prevents the protein from contacting with organic solvent and maintains the native conformation of the proteins, but also anchors protein to dsDNA in a fixed orientation and makes PCR amplification more efficient. The gene probe thus constructed is stable for at least 6 months at room temperature. This new approach is exquisite, simple, less expensive, and suitable to a variety of applications. The preliminary study on the detection of AFP using this novel probe was performed by immuno PCR, and the results indicated that the sensitivity of the gene probe by immuno PCR is 10 4-10 5 times higher compared with ELISA. The construction of immuno PCR gene probe in this way not only completely prevents the protein from contacting with organic solvent and maintains the native conformation of the proteins, but also anchors protein to dsDNA in a fixed orientation and makes PCR amplification more efficient. The gene probe thus constructed is stable for at least 6 months at room temperature. This new approach is exquisite, simple, less expensive, and suitable to a variety of applications.