A　new　split-type　photoelectrochemical　(PEC)　immunosensing　platform　was　designed　for　sensitive　detection　of　aflatoxin　B1　(AFB1)　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-AFB1　antibody-conjugated　magnetic　bead　by　using　alkaline　phosphatase　(ALP)-labeled　bovine　serum　albumin-AFB1　(AFB1-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　Co2+　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　AFB1　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.