Ni foam supported photocathode platform for DNA detection based on antifouling interface

•A novel antifouling DNA sensor is proposed for BRCA1 ultrasensitive detection.•The needle-like Eu:Co3O4 was in situ synthesized on conductive Ni foam as the basic photocathode.•CuS nanoparticles was grown on the surface of Eu:Co3O4/Ni foam through a SILAR to enhance the PEC response.•The antifouling interface was applied for DNA sequence fixing to improve the sensitivity of the sensor.•The sensor for BRCA1exhibits a low detection limit of 0.38 fM. In this work, the photosensitive needle-like Eu: Co3O4 was synthesized on conductive nickel foam (Ni foam) in situ via hydrothermal and subsequent heat treatment, and as the basic material to construct an antifouling photoelectrochemical (PEC) DNA sensor for BRCA1 (breast cancer marker) detection. Ni foam has a great frame structure, which could well control the morphology and size of materials. Then CuS nanoparticles could easily grow on the surface of Eu: Co3O4/Ni foam through a sequential ionic layer adsorption reaction to further enhance the PEC response. For BRCA1 sensitivity analyzing, the excellent antifouling property was realized rely on the conjugation of amino-terminal poly(ethylene glycol) (PEG-NH2). The developed PEC sensor displayed an outstanding stability and great sensitivity under the dissolved oxygen environment, and Ni foam PEC electrode provided potential application for other photosensitive materials-controlled preparation.