Wearable nanobiosensor for automatic in situ analysis of circulating proteins and hormones

The quantification of trace-level protein or hormone biomarkers in blood at picomolar-level sensitivity requires labor-intensive incubation and washing steps. Sensing proteins and hormones in sweat, which would allow for point-of-care monitoring, is hindered by the typically large interpersonal and intrapersonal variations in its composition. In this talk, I will discuss the design and performance of wearable and wireless devices for the real-time electrochemical detection of trace-level proteins (i.e., inflammatory biomarker C-reactive (CRP)) and hormones (i.e., estradiol) in sweat. These devices integrate iontophoretic sweat extraction, microfluidic channels for precise sweat sampling, and a biosensor array for quantifying the protein or hormone biomarkers, ionic strength, pH and temperature for the real-time calibration of the biosensor. I will also introduce our efforts in evaluating and validating these wearable sensors in human subjects. In patients with chronic obstructive pulmonary disease, with active or past infections or who had heart failure, the elevated concentrations of CRP measured via the patch correlated well with the protein’s levels in serum. Our data suggests a cyclical fluctuation in sweat estradiol during menstrual cycles, and a high correlation between sweat and blood estradiol was identified. Such wearable biosensors for the real-time sensitive analysis of trace-level protein and hormone biomarkers in sweat could facilitate personalized healthcare and disease management.