Target Peptide Detection and Measurement Using a Capacitive Immunoprobe Biosensor

Begin with an assembled perfluoroalkoxy-coated platinum wire with a polydopamine layer.

Soak this probe in a solution containing target peptide-specific antibodies, which immobilize on polydopamine, forming an immunoprobe. 

Wash and place the immunoprobe in a flow chamber with a silver chloride ground electrode, establishing a circuit.

First, introduce the buffer and apply a voltage to activate the immunoprobe, enabling it to function as a battery or capacitor, storing energy as an electrical charge.

Record the electrical signal to generate the baseline.

Now, expose the biosensor to a solution containing the target peptides.

These peptides bind to the antibodies on the probe, causing an alteration in the local charge and the energy stored in the biosensor.

Record the electrical signal. An increase in signal indicates the presence of the target peptide, while the magnitude of this signal correlates with the target peptide concentration.