Detection of anti-p53 autoantibodies in saliva using microfluidic chips for the rapid screening of oral cancer

Autoantibodies have high specificity and stability and are easy to detect. Anti-p53 autoantibodies can be used as biomarkers for the early detection of oral cancer. However, most studies detected anti-p53 in sera samples. In this study, a microfluidic chip combined with magnetic immunoassay, which can automatically detect the concentration of anti-p53 in saliva, was developed. The use of a micromixer can shorten the immunoassay time: the mixing time of the antigen and antibody can be reduced from the original 60 min off-chip to 20 min, making the total immunoassay time around 60 min. A method of moving magnetic beads and the antibody instead of manipulating fluid was utilized to simplify fluid control and decrease contamination caused by non-specific protein adsorption to the surface of reaction wells. The detection limit of anti-p53 was 4 ng mL^-1. In addition, a relative concentration of anti-p53 in the saliva of patients was detected in the chip.