Insulin surface acoustic wave immunosensor based on immobilized C60/anti-insulin antibody

Immobilized fullerene C-60/anti-insulin antibody was prepared and applied in shear horizontal surface acoustic wave (SH-SAW) immunosensors to detect insulin in aqueous solutions. The immobilizations of anti-insulin onto fullerene were studied through a C-60/PVC coated SH-SAW sensor system in liquid. The partially irreversible frequency response for an anti-insulin antibody was observed by the desorption study, which implied that fullerene could chemically react with anti-insulin. C-60/anti-insulin coating materials were successfully prepared and identified with an FTIR spectrometer. The C60/anti-insulin coated SH-SAW immunosensors were developed and applied for detection of insulin in aqueous solutions. Within the range of normal human insulin concentration, the SH-SAW immunosensors immobilized with C-60/anti-insulin exhibited linear frequency responses to the concentration of insulin with a sensitivity of 130 Hz/pM. The SH-SAW immunosensor immobilized with C-60/anti-insulin showed a detection limit of 0.58 pM for insulin in aqueous solution. The interference of various common bio-species in human blood, e.g. urea, ascorbic acid, tyrosine, and metal ions, to the SH-SAW immunosensor immobilized with C-60/ anti-insulin for insulin was investigated. These common bio-species interferences showed nearly no interference to the SAW immunosensors coated with C-60/anti-insulin. The reproducibility of the SH-SAW immunosensor immobilized with C-60/anti-insulin for insulin was also investigated and is discussed.