Hydrogel　coatings　of　catheters　have　attracted　extensive　attention　in　the　field　of　medical　devices　due　to　its　hydrophilicity　and　softness,　while　scarcities　of　Janus　adhesion,　adaptive　antibacterial　property,　and　real-time　disease　monitoring　restricted　their　clinical　translational　applications.　Herein,　a　novel　hydrogel　coating　with　water-responsive　Janus　adhesion　and　acidity-triggered　transformation　was　fabricated　for　antibacterial　treatment　and　fluorescence　diagnosis　of　catheters-associated　infections.　First,　a　sufficient　adhesion　strength　of　44.6　±　1.9　kPa　effectively　prevented　shedding　of　the　hydrogel　coating　during　catheterization,　and　meanwhile　a　super-lubricated　layer　with　an　extremely-low　coefficient　of　friction　of　about　0.03　was　formed　to　reduce　friction　pain　in　an　aqueous　microenvironment.　Furthermore,　size　and　fluorescence　intensity　of　chitosan/bovine　serum　albumin-gold　nanoparticles　within　the　hydrogel　were　varied　with　pH　due　to　acidity-triggered　transformation,　where　an　adaptive　release　of　antibacterial　nanoparticles　was　achieved　to　reduce　biofilms　formation　and　alleviate　inflammation　degree　synergistically.　More　importantly,　such　antibacterial　treatment　was　monitored　in　real-time　dependent　on　an　on–off　variation　of　fluorescence　intensity.　Overall,　amounts　of　in-vitro　and　in-vivo　results　performed　in　rabbit　urinary　tract　infection　model　and　porcine　tracheal　intubation　model　fully　suggested　our　newly-synthesized　hydrogel　coating　on　universal　medical　devices　showed　a　promising　potential　for　integrated　diagnosis　and　treatment　of　catheters-associated　infections.　©　2024　Elsevier　B.V.