Fig. 7.
(a) Schematic illustration of an rGO-coated electrochemical immunosensor (chip) which is integrated with a microfluidic platform. EDC-NHS coupling improves the immobilization of antibodies capturing H1N1 influenza virus. The redox active marker [Fe(CN)6]3-/4- is present in the sample solution. Electrochemical response of BSA/Ab/rGO/CA/Au (BSA: Bovine serum albumin, CA: cysteamine) electrode as a function of H1N1 virus concentration was obtained using the chronoamperometric technique. The chronoamperometric current increases proportionally with the H1N1 virus concentration in the range of 1 to 104 PFU mL−1. (b) SEM of rGO/CA/Au and (c) Ab/rGO/CA/Au after capture of H1N1 virus. (d) Chronoamperometric response of the BSA/Ab/rGO/CA/Au-based immunochip as a function of H1N1 virus concentrations. The experiment was controlled using a syringe pump attached to the inlet of the microsystem (inset: response current of BSA/Ab/rGO/CA/Au immunosensing chip with (i) or without (control) H1N1 virus concentration). (e) Calibration plot showing H1N1 virus concentrations (PFU mL−1) and the amperometric current of the immunochip during sensing. Adapted from (Singh et al., 2017). Copyright © 2017 Springer Nature is licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/).