Detecting low concentrations of biomarkers is a big challenge. The signals are often too weak for conventional methods.
In electrochemistry, redox probes are typically used to amplify these interactions at the electrode surface. However, they can degrade electrodes, affect reproducibility, and potentially harm some biomarkers.
With high-frequency impedance spectroscopy, we demonstrate an alternative. Changes as small as 0.2 pF are undetectable at low frequencies, but become clearly resolvable when the measurement is pushed into the MHz range. This is exactly where the ECA-5M was designed to operate.
This opens the door to label-free, redox-probe-free biosensing for biomarkers that were previously out of reach.
