Clean Technology 2008
S. Huang, H. Yang, M. Johnson, J. Wan, I. Chen, V.A. Petrenko, B.A. Chin
Auburn University, US
magnetoelastic, biosensor, phage, annealing, gold, bundling, Bacillus anthracis spores
A magnetoelastic (ME) platform coated with a bio-molecular recognition element (bacteriophage) for selective and specific recognition of Bacillus anthracis spores is described. ME materials have a mass-sensitive, characteristic, resonant frequency. In response to the binding of spores to the phage on the biosensor, a corresponding decrease occurs in the resonance frequency, enabling bio-detection real time and in-vivo. Experiments were performed to determine the optimum gold layer thickness and annealing condition for the prevention of sensor corrosion in aqueous environments. It was found that a 100 nm gold layer provides corrosion resistance as well as biocompatibility (phage immobilization). It was also determined that vacuum annealing at 200-250°C will increase the platform’s environmental stability, as well as signal Q-factor. It is also important to determine the ideal conditions for the immobilization of phage onto the gold surfaces of the sensor platforms. The concentration of phage and salt in solution must be optimized to reduce bundling of the phage filaments, which determines the overall binding affinity of the biosensor. Based on the sensor response and SEM results, a phage concentration of 11011 vir/ml and a salt concentration of 420 mM in 1x TBS provide the best sensor performance in terms of binding sensitivity.