In　recent　years,　the　development　of　miniature　and　portable　sensors　has　been　a　major　focus　of　research.　PEC　self　powered　sensors　have　emerged　as　a　potential　solution　to　the　power　supply　issue,　eliminating　the　need　for　external　power　supplies　and　operating　without　bias　voltage.　This　study　developed　a　ZnO/Au/GaN　sensor　for　highly　sensitive　detection　of　alpha-fetoprotein　(AFP).　The　sensor　uses　GaN　substrates　with　nanogold　films　to　provide　an　auxiliary　bias　voltage,　promoting　high　photogenerated　current　density.　Using　ZnO/Au/GaN　as　a　photoanode　resulted　in　significantly　higher　photocurrent　generated　by　the　sensor　compared　to　Au/GaN　or　ZnO/　ITO　alone.　To　enable　selective　detection　of　AFP,　antibody　modification　of　the　ZnO　nanorod　arrays　was　employed.　The　linear　range　of　the　sensor　response　to　AFP　was　determined　to　be　0.080-5.0　ng/mL,　with　an　impressively　low　detection　limit　of　0.027　ng/mL　(S/N　=　3).　These　results　demonstrate　the　potential　of　this　self-powered　sensor　for　detecting　AFP　content　in　human　serum　samples.　Overall,　this　study　presents　a　novel　approach　for　developing　highly　sensitive　and　selective　self-powered　sensors　for　biomarker　detection,　which　could　facilitate　early　detection　and　clinical　diagnosis　of　various　types　of　cancer.