Photoelectrochemical biosensor and methods of use thereof

A biosensor for detecting a target analyte in a sample comprising:

• a) a first photoelectrode comprising a conductive substrate and a photoactive material;
• b) a second photoelectrode comprising a conductive substrate and a photoactive material;
• c) a first capture probe functionalized on the first photoelectrode;
• d) a second capture probe functionalized on the second photoelectrode;
• and
• e) optionally one or more reporter moieties comprising a detectable label;
• wherein the first capture probe and the second capture probe each, independently, provides a distance between the detectable label and the photoactive material in the presence of the target analyte,
• wherein intensity of detection signal dictated by the distance is generated from the first photoelectrode and the second photoelectrode by transfer of electrons between the detectable label and the photoactive material, and
• wherein a higher intensity of the detection signal from the first photoelectrode as compared to the second photoelectrode in the presence of the sample, or a higher increase in the intensity of the detection signal from the first photoelectrode as compared to the second photoelectrode in the presence of the sample as compared to in the absence of the sample, is indicative of the presence of the target analyte.