Optimization of Phage-Based Magnetoelastic Biosensor Performance

A magnetoelastic (ME) platform coated with a biomolecular recognition element (bacteriophage) for selective and specific recognition of Bacillus anthracis spores is described. ME materials have a mass-sensitive, characteristic, resonance frequency. In response to the binding of spores to the phage on the ME biosensor, a corresponding decrease occurs in this resonance frequency, which enables the possibility of real time and in-vivo biodetection. Experiments were performed to determine the annealing condition for the prevention of corrosion in aqueous environments. It was found that annealing at 200250°C in a vacuum oven after gold deposition can effectively increase the ME platform's environmental stability, as well as the Q-factor and mass sensitivity of the ME biosensor. Another set of variables involves the concentration of phage suspension as well as the concentration of salts contained in phage solution. Based on the sensor response and SEM results, a phage concentration of 1×10 vir/ml and a salt concentration of 420 mM in 1x TBS provide the best sensor performance in terms of binding sensitivity.