Excessive　reactive　oxygen　species　(ROS)　in　seminal　plasma　can　trigger　male　infertility.　Therefore,　the　development　of　simple　and　rapid　ROS　detection　methods　is　urgently　needed,　particularly　for　the　early　self-screening　of　preconception　couples.　Herein,　a　gold　nanobipyramid　(Au　NBP)-based　colorimetric　hydrogel　for　convenient　and　fast　ROS　detection　is　described.　In　the　hydrogel,　Au　NBP　is　etched　efficiently　by　ROS　under　the　synergistic　effect　of　Fe2+and　I−,　which　finally　causes　color　variations.　Besides,　agarose　gel　with　the　function　of　molecular　sieve　enables　the　separation　of　biomacromolecules,　improving　the　interference　resistance　of　the　system　and　the　stability　of　Au　NBP.　This　chemical　sensor　can　complete　all　the　tests　within　20　min,　covering　two　detection　range　of　10–125　μM　at　relative　low　H2O2　concentration　and　125–1000　μM　at　relative　high　H2O2　concentration,　with　the　detection　limits　of　1.76　μM　and　12.10　μM　(S/N　=　3)　respectively.　Furthermore,　via　visual　observation　of　the　color　variations,　it　allows　the　initial　interpretation　of　ROS　concentration　without　any　additional　equipment.　We　applied　this　device　to　the　detection　of　ROS　in　clinical　seminal　plasma　samples　and　obtained　promising　results,　demonstrating　its　potential　for　rapid　and　convenient　detection　in　clinical　applications.　©　2024　Elsevier　B.V.