Bacteriophage tail-spike protein derivitized microresonator arrays for specific detection of pathogenic bacteria

Increasing concerns about food safety have prompted strong interest in the development of new pathogen detection technologies. The currently used techniques usually rely on specially equipped laboratories and are labor-intensive and time-consuming. Microresonator-based biosensors incorporating specific biorecognition probes are promising for the development of highly sensitive bacterial detection sensors. We present an optimized microresonator array platform that uses phage tail-spike proteins as a recognition probe. This array is composed of one thousand beams in a small area (i.e. 13.5 mm2 area) and therefore offers large surface area for capture of bacteria. These resonators feature a high natural frequency due to the optimized beam design, with the first resonance frequency at f0 = 1.095 ± 0.005 MHz. Theoretical analysis of these devices indicates a high mass sensitivity with a threshold for the detection of added mass as small as δm = 52 fg (lighter than a single bacterial cell). FEA and the experimental results show that the frequency shift is mainly due to the mass loading effect of adsorbed bacteria. We have successfully demonstrated the application of these arrays for specific detection of Campylobacter jejuni cells after immobilization of devices with phage GST-Gp48 tail-spike proteins. TSP-functionalized devices did not show any sensitivity to Escherichia coli bacteria confirming the specificity of detection.