Novel peptides functionalized gold nanoparticles decorated tungsten disulfide nanoflowers as the electrochemical sensing platforms for the norovirus in an oyster

Human norovirus is one of the potential foodborne pathogens causing acute gastroenteritis, diarrhea, and food poisoning. For norovirus detection, we developed the norovirus specifically capturable peptides functionalized gold nanoparticles (AuNP) decorated tungsten disulfide nanoflower (WS₂NF/AuNP). Based on the 3D-structured WS₂NF acting as a supporting material, AuNP were immobilized on its surface to assist the conductivity of WS₂NF and provide effective immobilization sites for bioreceptors. Since norovirus is composed of protein that functions as an insulant, as the virus bind with WS₂NF/AuNP, the impedance is elevated by hindering the charge transfer between the working electrode and redox species ([Fe(CN)₆]^3-/4-). The prepared nano-bio hybrid sensor was assessed by electrochemical impedance spectroscopic technique with spiked samples and deliberately infected oyster samples, respectively. In the case of the former, the electrochemical sensor represents a low detection limit (2.37 copies/mL) with a detection range from negative control to 10⁴ copies/mL, and it was shown a detection limit of 6.21 copies/mL even in the oyster samples. Besides, when it applies to the different types of viruses such as rotavirus and dengue virus to verify the selectivity of this system, there were no effective signals except the norovirus. Therefore, it revealed that combining WS₂NF and AuNP enhances electrochemical activity and stability via mutual synergetic effects.