Biosensor based on hybrid nanocomposite and CramoLL lectin for detection of dengue glycoproteins in real samples

We describe the development of a biosensor to distinguish abnormal glycoproteins of sera from patients infected with dengue serotypes I, II and III (DSI, DSII and DSIII). In addition, electrochemical analyses for patients infected with dengue fever (DF) and dengue hemorrhagic fever (DHF) were also performed. Cratylia mollis (CramoLL) lectin was immobilized by electrostatic interactions on hybrid nanocomposite composed by gold nanoparticles (AuNps) and polyaniline (PANI). The characterization was performed by means of electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and scanning electron microscopy (SEM). CV and EIS data showed a larger blockage of charge transfer at the electrode surface modified with AuNps-PANI-CramoLL-DS as compared to AuNps-PANI-CramoLL. AuNps-PANI-CramoLL-DSIII showed a higher charge transfer resistance (RCT). A small increase in the RCT was observed for DF in the presence of CramoLL, as compared to the DHF. SEM showed the presence of heterogeneous clusters after contact with glycoproteins present in dengue sera. CramoLL was able to recognize serum glycoproteins from different serotypes and stages of the infection, becoming a promisor candidate for development of new diagnosis protocol for dengue based on recognition of viral glycoproteins.