Fig. 2.

(a) The pseudo-double-gate structure of a MoS₂ biosensor. (b) Optical image of the MoS₂ bio-FET with insets representing a tapping-mode AFM image and its thickness profile. Shifts in the transfer curves for the MoS₂ bio-FET immobilized with (c) anti-PSA of 100 μg/mL, (d) PSA of 100 ng/mL and, (e) casein of 1% (w/v). (f) Transfer characteristics with PSA concentrations from 100 fg/mL to 1 ng/mL on the anti-PSA-immobilized MoS₂ bio-FET. (g) Plot of V_TH against PSA concentrations. Reprinted with permission from Ref. [42]. Copyright 2017, ACS Applied Materials & Interfaces.