Rapid virus detection using magnetic second harmonics of superparamagnetic iron oxide nanoparticles

Virus detection methods based on nonlinear magnetic response of magnetic nanoparticles have been investigated, and magnetic detection methods using the third harmonic are widely applied, owing to their high sensitivity and short measurement time. This paper proposes a virus detection method based on the second harmonic because of its larger signal component. We found that the second harmonic signal is superior to the third harmonic signal for small nanobeads and a large change of the second harmonic signal in the signal-to-noise ratio (SNR) with nanobeads concentration. In addition, a virus detection limit of 100 pg/ml is achieved. Therefore, the proposed method can potentially be utilized for rapid screening of viruses.

Automated summary

This study investigates virus detection methods based on the nonlinear magnetic response of magnetic nanoparticles, and the widely used magnetic detection methods using the third harmonic due to their high sensitivity and short measurement time. The paper proposes a virus detection method based on the second harmonic signal, which has a larger signal component. It is found that the second harmonic signal is superior to the third harmonic signal for small nanobeads, and it shows a large change in the signal-to-noise ratio (SNR) with nanobeads concentration. Additionally, a virus detection limit of 100 pg/ml is achieved. Therefore, the proposed method has the potential to be used for rapid screening of viruses.