Sense and… Fertility

Researchers at the California Institute of Technology, Pasadena, USA, have developed a skin-interfaced wearable aptamer nanobiosensor that enables automatic and non-invasive monitoring of hormones in women (1). The goal? To deliver personalized reproductive healthcare for the benefit of both patients and clinicians.

As for the sensing strategy, the team coupled a highly sensitive estradiol nanobiosensor with an iontophoresis module for autonomous sweat induction at rest, capillary bursting valves for precise microfluidic sweat sampling, and multiplexed temperature, pH and ionic strength sensors for real-time calibration.

The authors claim the sensor offers “extraordinary sensitivity” – which they attribute to a gold nanoparticle-MXene electrode. “The signal we got from gold nanoparticle-MXene electrodes showed nearly 20 times improvement in sensitivity compared to that from clean-room evaporated gold electrodes when using the same sensing strategy,” says Wei Gao, Assistant Professor of Medical Engineering and corresponding author of the paper. “Combining the gold nanoparticle-MXene electrode with our unique sensor strategy, we could realize pM level sensitivity for in situ sweat analysis.”

The aptamer biosensor was validated in human participants, who reported positive feedback without experiencing discomfort or difficulty. And with those people in mind, the researchers also took privacy seriously. “Data security and privacy are of great importance for personalized data collection using wearable sensors,” says Gao. “During the human trials, we only collect de-identified data from the human subjects. In future practical use, we will work with cyber security experts to make sure data will be safely collected and secured.”

The team hopes their wearable sensor could be used as a standalone wearable device (similar to a smartwatch or smart ring) or be integrated with an existing wearable platform, with possible adaptation to monitor other low-level clinically relevant protein and hormone biomarkers.