Visual simultaneous detection of single nucleotide polymorphism of tumor susceptibility gene and marker alpha-fetoprotein based on double-labeled colloidal gold probe with lateral flow strip biosensor

Liver cancer is one of the most common cancers in the world. The gene CYP1A1 is closely related to the occurrence of cancer, and the tumor marker alpha-fetoprotein (AFP) is also one of the important indicators for liver cancer screening. Therefore, detection of these two substances is of great significance. In this paper, a test strip biosensor capable of simultaneously detecting cancer susceptibility gene CYP1A1 and AFP has been established. There were two detection lines in the strip biosensor, one was used for qualitative detection of susceptible gene by base complementary pairing, and the other was used for semi-quantitative detection of AFP by antigen-antibody reaction. Finally, signal amplification was achieved by horseradish peroxidase catalyzing substrate 3-amino-9-ethylcarbazole. Results showed that under the optimized conditions, the strip biosensor had a good linear relationship (R-2 = 0.987) when AFP concentration was in the range of 20-250 ng/mL, and the other hundred times of proteins had no obvious interference to the detection, indicating that the method presented good selectivity. The detection of susceptibility gene CYP1A1 and AFP in real blood samples by the strip was in accordance the standard method, which showed that the method had good accuracy and could be used for qualitative judgment of SNP locus base type of susceptibility gene and semi-quantitative detection of tumor marker in real sample, so it had a good application potential.