Protein detection method

A method for electrochemical detection of a viral antigen, comprising:

• providing a nanostructured microelectrode including a linker on its surface, the linker attached to an antibody or fragment thereof and capable of binding the antigen;
• contacting the nanostructured microelectrode with a sample including the antigen and with a redox reporter capable of electron transfer with the microelectrode;
• binding of the antigen to the antibody or fragment thereof, the binding hindering electron transfer between the redox reporter and the nanostructured microelectrode, the nanostructured microelectrode having a diameter of about 100 microns or less, the nanostructured microelectrode having a detection limit for the antigen from about 0.1 U/ml to about 10 U/ml;
• applying a potential to the nanostructured microelectrode;
• measuring, in response to the applied potential, an electrochemical signal generated by the nanostructured microelectrode;
• comparing the electrochemical signal to a control signal;
• and
• deeming a change of the electrochemical signal detected relative to the control signal as indicative of the presence of the viral antigen in the sample.

A method for electrochemical detection of an antigen, comprising:

• providing a nanostructured microelectrode including a cystamine, cysteamine, mercapto propionic acid or 4-aminothiophenol linker on its surface, the linker attached to an antibody or fragment thereof and capable of binding the antigen;
• contacting the nanostructured microelectrode with a sample including the antigen and with a redox reporter capable of electron transfer with the microelectrode;
• binding of the antigen to the antibody or fragment thereof, the binding hindering electron transfer between the redox reporter and the nanostructured microelectrode, the nanostructured microelectrode having a diameter of about 100 microns or less, the nanostructured microelectrode having a detection limit for the antigen from about 0.1 U/ml to about 10 U/ml;
• applying a potential to the nanostructured microelectrode;
• measuring, in response to the applied potential, an electrochemical signal generated by the nanostructured microelectrode;
• comparing the electrochemical signal to a control signal;
• and
• deeming a change of the electrochemical signal detected relative to the control signal as indicative of the presence of the antigen in the sample.

A method for electrochemical detection of a cancer biomarker, comprising:

• providing a nanostructured microelectrode including a linker on its surface, the linker attached to an antibody or fragment thereof and capable of binding the biomarker;
• contacting the nanostructured microelectrode with a sample including the biomarker and with a redox reporter capable of electron transfer with the microelectrode;
• binding of the biomarker to the antibody or fragment thereof, the binding hindering electron transfer between the redox reporter and the nanostructured microelectrode, the nanostructured microelectrode having a diameter of about 100 microns or less, the nanostructured microelectrode having a detection limit for the biomarker from about 0.1 U/ml to about 10 U/ml;
• applying a potential to the nanostructured microelectrode;
• measuring, in response to the applied potential, an electrochemical signal generated by the nanostructured microelectrode;
• comparing the electrochemical signal to a control signal;
• and
• deeming a change of the electrochemical signal detected relative to the control signal as indicative of the presence of the cancer biomarker in the sample.