Performance evaluation of charge plasma based dielectrically tuned JFTFET for label-free detection of breast cancer biomarkers

Abstract

Present manuscript describes the identification of breast cancer (BC) cell lines (MDA-MB-231, MCF-7, Hs578T, and T47D) and normal breast cells (MCF-10A) by analyzing modifications in their electrical features using a charge plasma-based dielectrically tuned junctionfree tunnel FET (CP-DT-JFTFET). Dielectrically tuned (DT) FETs have gained significant attention for their application in label-free BC cell line detection. However, native short-channel phenomena hinder their sensitivity, energy efficiency, and scalability. Hence, to fully recognize the potential of DTFET biosensors, a pioneering initiative is underway to rapidly detect biomarkers associated with the breast cancer cells. The proposed design allows for the integration of a nanogap cavity located at the source side inside the gate oxide through precise etching, providing enhanced stability for anchored BC cell lines. When cancer cells become trapped in the patterned nanocavities—previously occupied by air—the dielectric constant of these cavities is altered. This change leads to a variation in the electrical characteristics of the device, which can then be calibrated to identify BC cell lines. The reported CP-DT-JFTFET exhibits enhanced sensitivity for identifying breast cancer cells. The sensitivity of the CP-DT-JFTFET biosensor is evaluated in regard to ON current (I_ON), I_ON/I_OFF, transconductance (g_m), transit time ($\tau$), threshold voltage (V_TH), sub-threshold swing (SS), and so on. The presented biosensor demonstrates its highest sensitivity for the T47D (k = 32) BC cell line, exhibiting S_ION = $6.50\times {10}^3$, $S_{g_m}=6.51\times {10}^3$, $S_{\tau }=5.2\times {10}^3$, $S_{\text{VTH}}=0.76$, and $S_{\text{SS}}=1.5$. Furthermore, the effect of non-uniform cell line confinement inside the cavity has also been inspected to thoroughly assess the designed biosensor's capability to identify BC cell lines.