Ethyl　carbamate,　a　substance　frequently　occurring　in　fermented　foods,　seriously　affects　people＇s　health;　however,　poor　sensitivity　constrains　the　development　of　ethyl　carbamate　sensors.　In　this　work,　hierarchical　Bi2S3/MXene　nanosheets　were　synthesized　using　a　hydrothermal　method,　and　experimentally　their　coupled　UV　light　is　an　efficient　NH3　sensing　material.　Meanwhile,　the　density　functional　theory　(DFT)　confirms　that　the　MXene/Bi2S3　nanosheet　interface　has　an　excellent　ability　to　adsorb　NH3,　resulting　in　a　change　of　photocurrent.　As　a　proof-of-concept,　a　highly　sensitive　ethyl　carbamate　photoelectrochemical　(PEC)　biosensor　was　constructed　based　on　the　ammonia　generation　strategy　of　glutamate　dehydrogenase　coupled　to　the　branched　hybridization　chain　reaction　(bHCR).　Specifically,　the　target-triggered　bHCR　enriches　a　large　number　of　enzyme-encapsulated　liposomes,　while　the　enzymatic　NH3-generation　reaction　will　cause　a　change　in　the　Bi2S3/MXene　photocurrent,　which　completes　the　target　detection　process.　Under　optimal　conditions,　the　constructed　PEC　biosensors　exhibited　superior　analytical　performance　toward　ethyl　carbamate　in　the　range　of　0.01　μg/mL　to　1　μg/mL　and　limit　of　detection　(LOD)　down　to　0.001　μg/mL.　In　addition,　it　offers　an　effective　method　for　food　safety　monitoring　due　to　its　excellent　stability,　fast　response,　and　maneuverability　on　real　samples　(red　wine,　yellow　wine,　and　brandy).　©　2023　Elsevier　B.V.