Zearalenone　(ZEN)　is　a　common　contaminant　in　crops　with　serious　food　safety　implications.　By　leveraging　the　etching　effect　of　H2O2　on　gold　nanorods　(Au　NRs)　and　the　catalysis　of　Fenton　reaction,　we　have　successfully　developed　two　enzyme-linked　immunosorbent　assay　(ELISA)　kits　with　distinct　principles.　ZEN　can　be　accurately　quantified　by　both　methods　by　measuring　changes　in　the　longitudinal　surface　plasmon　resonance　(LSPR)　absorption　peaks　of　Au　NRs.　Direct　detection　kit　is　simpler　and　faster,　with　a　linear　range　of　0.2–4000　ng/mL,　while　indirect　competitive　kit　is　more　complex　and　has　a　narrower　linear　range　of　0.02–10　ng/mL.　This　study　is　expected　to　provide　an　effective　analytical　strategy　for　rapid　screening　and　accurate　monitoring　of　mold　contaminants　in　food　and　agricultural　products.　In　this　study,　a　novel　dual-mode　ELISA　system　was　developed　for　the　detection　of　zearalenone　(ZEN)　using　Au　NRs　and　their　longitudinal　surface　plasmon　resonance　(LSPR)　properties.　By　integrating　H₂O₂-mediated　nano-etching　and　Fenton　reaction　catalysis,　the　system　enables　both　direct　(0.2–4000　ng/mL)　and　indirect　competitive　(0.02–10　ng/mL)　detection　modes.　The　main　work　includes:　(1)　replacing　the　traditional　enzyme　colorimetric　signal　with　an　LSPR　shift　for　accurate　UV-visible　quantification　and　visual　multicolor　readout;　(2)　optimizing　the　nanoenzyme　catalytic　system　for　improved　reaction　sensitivity;　(3)　eliminating　the　need　for　enzyme-labeled　secondary　antibodies　in　direct　mode,　thereby　reducing　cost　and　improving　stability.　The　system　was　validated　on　grain　samples　with　recoveries　of　93.1-107.1%　and　detection　limits　of　0.2　ng/mL　(direct)　and　0.02　ng/mL　(indirect).　The　modular　design　of　the　method　allows　it　to　be　used　for　the　detection　of　other　mycotoxins　(e.g.,　aflatoxin,　ochratoxin)　and　offers　great　potential　for　food　safety　screening,　agricultural　monitoring,　and　environmental　assessment.　This　work　provides　a　cost-effective,　sensitive　and　versatile　platform　for　mycotoxin　analysis.　©　The　Author(s),　under　exclusive　licence　to　Springer　Science+Business　Media,　LLC,　part　of　Springer　Nature　2025.