Single-step label-free hepatitis B virus detection by a piezoelectric biosensor

In this paper we describe a single step and label free method to selectively detect the HVB genome based on hybridization with simple linear ssDNA probes immobilized on the Au surfaces of a QCM resonator. It has been proved that selective sensing ability is obtained for a large DNA target, constituted by an HBV clone of 7 kbps through a proper optimization of the probe density. Actually, with a probe density of ∼4.0 × 1012 molecules per cm2 we were able to detect fmol cm−2 of HBV target, without using any amplification steps or labelling method. The results presented herein pave the way to the development of an easy to use and portable PoC sensor device for direct and fast HBV detection.