A　new　split-type　photoelectrochemical　(PEC)　immunosensing　platform　was　designed　for　sensitive　detection　of　aflatoxin　B　1　(AFB　1　)　in　foodstuffs,　coupling　with　enzymatic　hydrolysate-triggered　etching　reaction　of　cobalt　oxyhydroxide　(CoOOH)　on　cadmium　sulfide　(CdS)　nanoparticles-functionalized　interface.　Initially,　the　photosensitive　electrode　was　prepared　by　coating　CoOOH　nanosheets　on　the　surface　of　CdS　nanoparticles　to　quench　the　photocurrent.　Thereafter,　a　competitive-type　enzyme　immunoreaction　was　carried　out　on　monoclonal　anti-AFB　1　antibody-conjugated　magnetic　bead　by　using　alkaline　phosphatase　(ALP)-labeled　bovine　serum　albumin-AFB　1　(AFB　1　-BSA)　conjugate　as　the　competitor.　With　the　formation　of　immunocomplex,　the　carried　ALP　hydrolyzed　ascorbic　acid　2-phosphate　(AAP)　into　ascorbic　acid　(AA)　and　phosphate.　The　former　ascorbic　acid　produced　etched　or　dissolved　CoOOH　nanosheets　into　Co　2+　ions,　thus　resulting　in　the　exposure　of　CdS　nanoparticles　on　the　surface　to　enhance　the　photocurrent　of　the　modified　electrode.　Under　optimum　conditions,　the　photocurrent　decreased　linearly　with　the　increasing　AFB　1　concentration　in　the　dynamic　range　of　0.01–10　ng　mL　−1　,　and　the　limit　of　detection　was　2.6　pg　mL　−1　.　The　precision　of　this　method　(expressed　as　RSD)　was　±8.6%.　In　addition,　the　accuracy　was　monitored　by　analyzing　spiked　food　samples,　and　gave　the　well-matched　results　with　the　referenced　ELISA　method.　©　2018　Elsevier　B.V.