Design and analysis of a resonant nano-bio-sensor based on carbon nanotubes to detect viruses

In this study, a theoretical model based on the modified nonlocal Euler-Bernoulli is presented for the detection of biologically adsorbed particles on doubly clamped carbon nanotubes as resonant nano-bio-sensors. The basis of the work of these resonant nano-bio-sensors is the accurate calculation of the change in the resonant frequency because of the change in the mass due to the surface adsorption of the viruses. In most studies, simply supported ends have been used for simplicity of calculations, while it is almost impossible to build such supports at nano-scale. For this purpose, a doubly clamped ends was used to analyze this problem and for the first time, the closed-form vibration frequency response of a doubly clamped nano-sensor was presented according to the geometric and mechanical characteristics of the nanotubes along with nonlocal, surface and rotary inertia effects. Although many researchers have ignored the effects of surface stress and rotary inertia on the vibration analysis of nano-sensors, this study found that these effects at nano-scale played a major role in changing the frequency and accuracy of resonant nano-bio-sensors. Also, based on the obtained results, six different types of viruses were examined. Based on the sensitivity analysis, the designed nano-bio-sensor was able to separate the frequency change and identify them, consequently.