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

Fabrication of the Au/MoS2/Au nanolayer on the PET substrate was confirmed by AFM and FE-SEM. Figure 3a -c shows AFM images of the PET substrate, Au sputter coated PET substrate, and Au/MoS2 on the PET substrate, respectively. In Figure 3a , the AFM results of the PET substrate indicated a height of 1.296 nm. When Au was sputter coated on the PET substrate, the height of the substrate increased to 7.856 nm due to the deposited Au as shown in Figure 3b . The MoS2 NPs immobilized on the Au coated PET substrate by spin coating was shown in Figure 3c , the height of the immobilized MoS2 NPs was about 155.81 nm. In addition, Figure 3d -f shows FE-SEM images of the fabricated Au/MoS2/Au nanolayer on the PET substrate. Compared to the results in Figure 3e , the existence of the sputter coated Au particles on MoS2 NPs was confirmed in Figure 3f . EDS analysis of all the acquired SEM images is shown in Figure S2 . The amount of sputter coated gold in the Au/MoS2/Au nanolayer on the PET substrate was doubled to the Au/MoS2 on the PET substrate due to the twice gold deposition. In addition, the EDS mapping result of the Au/MoS2/Au nanolayer on the PET substrate is shown in Figure S3 . Also, the CV result is shown in Figure 4a for confirmation of the fabrication of the Au/MoS2/Au nanolayer on the PET substrate. In Figure 4a , the CV results of the PET substrate showed no electrochemical signals, but signals were observed after Au sputter coating on the PET substrate. Also, the fabricated Au/MoS2/Au nanolayer on the PET substrate had higher electrochemical signals than the conventional bare gold electrode composed of gold (50 nm)/Cr (2 nm)/SiO2 (Silicon dioxide). The current increase of the Au/MoS2/Au nanolayer on the PET substrate compared to conventional bare gold electrode was due to the large surface area and the efficient electron transfer by MoS2 NPs.