Detecting low concentrations of biomarkers

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. As shown below, changes as small as 0.2 pF are undetectable at low frequencies, but become clearly measurable at high frequencies, hence no need for redox probes. Combined with our micro electrodes and test fixtures, this technology opens up new opportunities for label-free and sensitive biosensing.