Colorimetric aptasensor based on magnetic beads and gold nanoparticles for detecting mucin 1

In this work, a colorimetric aptasensor based on magnetic beads (MBs), gold nanoparticles (AuNPs) and Horseradish Peroxidase (HRP) was prepared for the detection of mucin 1 (MUC1). Complementary DNA of the MUC1 aptamer (Apt) immobilized on the MBs was combined with the prepared AuNPs-Apt-HRP complex (AuNPs@Apt-HRP). In the presence of MUC1, it specifically bound to Apt, resulting in the detachment of gold nanoparticles from the MBs. After magnetic separation, AuNPs@Apt-HRP was separated into the supernatant and reacted with 3,3',5,5'-Tetramethylbenzidine (TMB) to produce color reaction from colorless to blue. The linear range of MUC1 was from 75 to 500 μg/mL (R² = 0.9878), and the detection limit was 41.95 μg/mL. The recovery rate of MUC1 in human serum was 99.18 %∼101.15 %. This method is simple and convenient. Moreover, it does not require complex and expensive equipment for detection of MUC1. It provides value for the development of MUC1 colorimetric sensors and a promising strategy for the determination of MUC1 in clinical diagnosis.