Gold　metarsurfaces　are　widely　used　in　sensing　due　to　their　ability　to　enhance　localized　light　fields.　To　reduce　the　manufacturing　cost　of　gold　metasurfaces,　we　proposed　a　reusable　metasurface　biosensor　based　on　parylene　C　with　microfluidic　technology.　The　electric　field　distribution　of　the　gold　metasurface　was　simulated　using　the　Finite-Difference　Time-Domain　(FDTD)　method.　The　polydimethylsiloxane　(PDMS)　microfluidic　channels　were　bounded　on　the　surface　of　the　biosensor　to　provide　specific　reaction　area　to　detect　different　concentrations　of　NaCl　solution.　For　the　purpose　of　reusability,　the　growth　and　removal　of　parylene　C　on　the　metasurface　were　realized.　Besides,　the　parylene　C　film　acted　as　the　connection　layer　to　enable　the　one-step　physical　modification　of　antigen　and　antibody,　which　made　highly　efficient　biosensing　possible.　The　feasibility　of　this　approach　is　experimentally　validated　and　has　potential　to　be　widely　used　in　other　metasurface　biosensors.　©　2024　SPIE