Inadequate antigen capture and insufficient antigen-presenting cell (APC) activity at tumor sites limit the effectiveness of in situ vaccines. To address this, poly(glutamic acid-cholinephosphate) (pGluCP) is introduced as a polymer with cell membrane adhesion properties capable of capturing both water-soluble and insoluble membrane antigens from necrotic tumor cells while recruiting more APCs. The approach uses manganese-mineralized black phosphorus (MnBP) coated with pGluCP and αPD-1 antibodies to create the MnBP@pGluCP-αPD-1 complex for in situ vaccines. MnBP eradicates tumor cells via photothermal effects, releasing antigens, while Mn