Accurate　identification　of　acutely　toxic　and　low-fatality　mycotoxins　on　a　large　scale　in　a　quick　and　cheap　manner　is　critical　for　reducing　population　mortality.　Herein,　a　portable　photothermal　immunosensing　platform　supported　by　a　microelectromechanical　microsystem　(MEMS)　without　enzyme　involvement　was　reported　for　point-of-care　testing　of　mycotoxins　(in　the　case　of　aflatoxin　B1,　AFB1)　in　food　based　on　the　precise　satellite　structure　of　Au　nanoparticles.　The　synthesized　Au　nanoparticles　with　a　well-defined,　graded　satellite　structure　exhibited　a　significantly　enhanced　photothermal　response　and　were　coupled　by　AFB1　antibodies　to　form　signal　conversion　probes　by　physisorption　for　further　target-promoted　competitive　responses　in　microplates.　In　addition,　a　coin-sized　miniature　NIR　camera　device　was　constructed　for　temperature　acquisition　during　target　testing　based　on　advanced　MEMS　fabrication　technology　to　address　the　limitation　of　expensive　signal　acquisition　components　of　current　photothermal　sensors.　The　proposed　MEMS　readout-based　microphotothermal　test　method　provides　excellent　AFB1　response　in　the　range　of　0.5-500　ng　g-1　with　detection　limits　as　low　as　0.27　ng　g-1.　In　addition,　the　main　reasons　for　the　efficient　photothermal　transduction　efficiency　of　Au　with　different　graded　structures　were　analyzed　by　finite　element　simulations,　providing　theoretical　guidance　for　the　development　of　new　Au-based　photothermal　agents.　In　conclusion,　the　proposed　portable　micro-photothermal　test　system　offers　great　potential　for　point-of-care　diagnostics　for　residents,　which　will　continue　to　facilitate　immediate　food　safety　identification　in　resource-limited　regions.