Detection of cardiac biomarkers in serum using a micro-electromechanical film electroacoustic resonator

Rapid, portable, and sensitive biosensors for the detection of cardiac biomarkers are important for early diagnosis of cardiovascular diseases. We demonstrate a micro-electromechanical film electroacoustic resonator for heart-type fatty acid-binding protein assays. This device combines an immunologic sensitive element with the resonator working in biological liquids. Based on the mass-sensitive mechanism, the immune reaction between the target antigens and antibodies was detected by monitoring the frequency change in real-time and the concentration of heart-type fatty acid-binding protein in serum was determined. A linear response in 0.02-10 ng ml(-1) and a low detection limit of 0.014 ng ml(-1) were achieved. Serum samples were collected from patients and used without any additional pre-treatment. The protein concentrations measured by the proposed device showed good linear correlation and consistency compared with standard laboratory methods. The results indicate that the proposed device is able to be a feasible tool for sensitive, rapid, and miniaturized point-of-care analytical systems.