A biosensor based on a film bulk acoustic resonator and biotin-avidin system for the detection of the epithelial tumor marker mucin 1

AlN thin film bulk acoustic resonators (FBARs) with a resonant frequency of ∼575 MHz have been fabricated to function as an epithelial tumor marker mucin 1 (MUC1) biosensor. Streptavidin was assembled on the sensitive area of FBAR. After the recognition between aptamers-AuNP conjugates and MUC1, biotin, along with the conjugates, was captured by streptavidin onto the surface of FBARs. Therefore, the target MUC1 could be sensitively detected. This biosensor exhibited a good linear relationship between the frequency shifts and the concentrations of MUC1 ranging from 30 to 500 nM, which indicated the sensitivity is about 818.6 Hz nM −1 . The frequency shift remained relatively stable when the concentration of MUC1 was greater than 500 nM since the binding between MUC1 and aptamers-AuNP conjugates reached saturation. The selectivity experiment demonstrated that this biosensor can precisely detect MUC1 with good specificity. The positive results suggest that FBAR is an attractive alternative to a new approach for the detection of MUC1. A streptavidin-immobilized FBAR biosensor in virtue of specific binding between biotin and avidin was successfully fabricated for mucin 1 detection.