A Miniaturized Graphene-Based THz Biosensor for Noninvasive Early-Stage Breast Cancer Detection and TNM Staging

Abstract

Breast cancer (BC) is one of the predominant causes of cancer-related mortality among women worldwide. The rising incidence of BC highlights the critical need for portable medical devices that can detect malignancies in breast tissue at an early stage. This paper presents a miniaturized, noninvasive THz biosensor designed to detect the development of tumors in breast tissue at an early stage and determine the TNM stage of BC. The proposed graphene-based biosensor is placed over a SiO₂ substrate using metal radiators and graphene loads. The unique properties of graphene allow frequency reconfiguration ranging from 3.13 to 5.72 THz by adjusting its chemical potential (${\mu }_c$) through an external DC bias voltage. The proposed biosensor achieves an ultra-wide frequency band of 1.83 THz, a peak directivity of 7 dBi, and a peak gain of 6.1 dBi. Furthermore, a human breast phantom model, mimicking the dielectric characteristics of human breast tissue and nearby lymph nodes in the THz regime, has been developed. Reflectometry analysis is used to evaluate the biosensor's performance in detecting tumors ranging from 1 to 10 mm within breast tissue. Its performance is also evaluated at different angles and positions relative to the tissue, as well as in the presence of cancerous cells in nearby lymph nodes to determine the TNM (Tumor, Node, and Metastasis) staging of BC. The analysis results demonstrate that the proposed biosensor has the potential to detect tumor development in breast tissue at an early stage and determine the TNM stage of BC, making it suitable for both in vivo and ex vivo diagnostic applications.