Ultrasensitive WSe2 field-effect transistor-based biosensor for label-free detection of cancer in point-of-care applications

We demonstrate a highly sensitive tungsten diselenide (WSe2) field-effect transistor (FET) biosensor for label-free detection of early stage prostate cancer. We modified the FET channel by attaching the monoclonal antibody of prostate specific antigen (anti-PSA) through a multi-step process, followed by bovine serum albumin treatment, which ensures specific binding between anti-PSA and PSA. Our FET biosensor has a detection limit of 10 fg ml(-1) PSA, the lowest concentration detected so far by any FET sensor. At this detection limit, the sub-threshold swing is 235 mV dec(-1); and the drain current (I-d) in the FET increases by 70% compared to that in a pristine device. The FET sensor exhibits linear change in threshold voltage (Vth) and drain current (I-d) over the detection range of 10 fg ml(-1)-1 ng ml(-1) PSA. Our demonstrated ultra-sensitive and fast WSe2 FET biosensors are promising for point-of-care diagnostics applications.

Automated summary

We have developed a highly sensitive tungsten diselenide field-effect transistor biosensor for label-free detection of early stage prostate cancer. By modifying the FET channel and ensuring specific binding between anti-PSA and PSA, we achieved a detection limit of 10 fg ml(-1) PSA. This ultra-sensitive and fast FET biosensor shows promise for point-of-care diagnostics applications.