A Portable Salivary 17β-Estradiol Sensor with Label-free Organic Field-effect Transistor

Abstract

Monitoring 17β-estradiol hormones plays a key role in women’s health and fertility management. However, current detection methods predominantly rely on invasive blood tests and complex lab equipment, making them unsuitable for at-home use. In this study, we present an organic field-effect transistor (OFET)-based biosensor capable of detecting 17β-estradiol in saliva with high sensitivity and specificity. By passivating the gold electrode using a self-assembled monolayer and chemically grafting DNA aptamer onto the organic semiconductor, the OFET achieves stable operation for 17β-estradiol recognition in liquid environment. The sensor, herein, enables real-time, non-invasive hormone monitoring, with an ultra-low detection limit of 0.27 fg/mL and excellent selectivity in complex saliva samples. Moreover, we developed a portable biosensor, offering a convenient, at-home solution for hormone tracking. This advancement addresses the limitations of traditional estrogen detection in blood, paving the way for new approaches in personalized medicine and health monitoring.