A　colorimetric　and　photothermal　dual-mode　detection　method　based　on　β-NiOOH　nanozyme-3,3′,5,5′-tetramethylbenzidine　(TMB)　system　was　established　for　chloramphenicol　(CAP)　content　in　fruit　juice.　Herein,　a　novel　nanozyme　β-NiOOH　with　high　oxidase-like　activity　can　directly　and　effectively　catalyze　the　oxidation　of　colorless　TMB　to　blue　color　TMB　oxidation　(oxTMB)　without　the　presence　of　H2O2.　Using　a　competition-type　immunoassay,　the　oxTMB　can　induce　not　only　an　increase　in　the　absorption　peak　intensity　but　also　a　photothermal　effect　under　808　nm　laser　irradiation,　achieving　dual-mode　detection　of　CAP.　The　increase　of　absorbance　at　652　nm　and　the　increase　of　temperature　generated　by　photothermal　conversion　are　linearly　correlated　with　the　CAP　content.　Under　the　optimal　conditions,　the　dual-mode　detection　shows　a　low　limit　of　0.0056　ng　mL−1　for　the　colorimetric　method,　and　0.0016　ng　mL−1　for　the　photothermal　method.　Moreover,　the　developed　colorimetric　and　photothermal　dual-mode　immunobiosensor　was　successfully　used　to　detect　CAP　in　fruit　juice　with　an　acceptable　recovery　rate　between　93.387%　and　118.514%.　This　method　has　good　repeatability,　specificity,　and　accuracy,　and　provides　an　efficient　approach　for　real-time　detection　of　CAP　in　food　safety　analysis　and　detection　platforms.　©　2024　The　Royal　Society　of　Chemistry.