Oxidative　stress　caused　by　pregnancy-induced　hypertension　syndrome　significantly　affects　the　health　of　pregnant　women.　Hydrogen　sulfide　is　a　typical　gaseous　signal　molecule　against　oxidative　stress,　and　it　is　of　profound　significance　to　develop　a　detection　method.　In　this　study,　a　stimuli-responsive　hydrogel　was　constructed　based　on　the　coordination　and　bonding　principle　of　metal　ions　and　chitosan　(CS)　to　realize　the　quantitative　detection　of　hydrogen　sulfide　(H2S).　The　chain　of　CS　contains　a　large　number　of　amino　groups　and　hydroxyl　groups,　which　can　form　the　coordination　structure　with　Cu2+,　triggering　CS　to　form　a　stable　hydrogel.　The　hydrogel　can　be　formed　within　about　5　s,　which　has　the　characteristics　of　rapid　preparation.　In　the　presence　of　target　H2S,　the　cross-linking　agent　Cu2+　in　the　hydrogel　can　compete　out,　resulting　in　the　collapse　of　the　hydrogel　and　the　release　of　the　electrochemical　probe.　By　detecting　the　concentration　of　the　released　electrochemical　probe,　the　quantitative　detection　of　H2S　can　be　achieved.　The　prepared　hydrogel　has　a　good　linear　relationship　with　the　concentration　of　H2S　from　1　μM　to　60　μm.　At　the　same　time,　the　hydrogel　has　good　specificity　and　stability,　and　it　can　be　applied　to　the　detection　of　H2S　in　serum　samples.　©　2024　The　Authors.　ChemistryOpen　published　by　Wiley-VCH　GmbH.