Flexible HIV-1 Biosensor Based on the Au/MoS(2) Nanoparticles/Au Nanolayer on the PET Substrate

Shin, Minkyu; Yoon, Jinho; Yi, Chanyong; Lee, Taek; Choi, Jeong-Woo

CV and SWV were performed to confirm the electrochemical properties of the fabricated biosensor with a [Fe(CN)6] 3−/4− redox probe. Figure 4b shows the CV result of the Au/MoS2/Au nanolayer on the PET substrate, the Cys/Au/MoS2/Au nanolayer on the PET substrate, the Ab/Cys/Au/MoS2/Au nanolayer on the PET substrate. The reduction and oxidation peak currents of the Au/MoS2/Au nanolayer on the PET substrate was found to be 1.13 mA and −1.17 mA, respectively. After Cys immobilization, the reduction and oxidation peak potentials were changed from 0.05 V and 0.35 V to 0.12 V and 0.28 V, and the reduction and oxidation peak potentials were also increased to 1.36 mA and −1.37 mA, respectively. This increase was due to the electrostatic interaction between the negatively charged [Fe(CN)6] 3-/4-and the positively charged amine group of the Cys immobilized on the Au/MoS2/Au nanolayer on the PET substrate. However, when the gp120 antibody was immobilized on the Cys, the efficiency of electron transfer between the multilayer and the redox probe was reduced by the gp120 antibody, and the reduction and oxidation peak currents were lowered to 1.30 mA and -1.34 mA, respectively. In addition, to confirm the reproducibility of fabricated biosensor, the average reduction peak current was investigated with four different measurements. As shown in Figure S4 , the average reduction peaks of Au/MoS2/Au nanolayer on the PET substrate, Cys/Au/MoS2/Au nanolayer on the PET substrate and Ab/Cys/Au/MoS2/Au nanolayer on the PET substrate were 1.12 mA, 1.38 mA, and 1.30 mA. In Figure 4c , the CV results were obtained by increasing the scan rate from 10 mV/s to 200 mV/s to verify the relationship between the current peak and the scan rate of the fabricated the Au/MoS2/Au nanolayer on the PET substrate. Figure 4d showed that the plotted reduction and oxidation peak currents of the measured CV showed a linear response to the increase in the scan rate.