Unprecedented Organogermanium Functionalized GeIV−SbIII‐Templating Polyoxotungstate Nanocluster for Photothermal–Chemodynamic Cancer Therapy

Abstract The function‐oriented synthesis of polyoxometalate (POM) nanoclusters has become an increasingly important area of research. Herein, the well‐known broad‐spectrum anticancer drug Ge‐132 which contains Ge IV as potential heteroatoms and carboxyl coordination sites, is introduced to the POM system, leading to the first organogermanium functionalized Ge IV −Sb III ‐templating POM nanocluster Na 4 [H 2 N(CH 3 ) 2 ] 16 H 18 [Sm 4 (H 2 O) 12 W 4 O 14 Ge(CH 2 CH 2 COOH)] 2 [SbW 9 O 33 ] 4 [Ge(CH 2 CH 2 COOH) SbW 15 O 54 ] 2 ·62H 2 O ( 1 ). An unprecedented organogermanium templating Dawson‐like [Ge(CH 2 CH 2 COOH)SbW 15 O 54 ] 12− building block is discovered. To take advantage of the potential pharmaceutical activity of such an organogermanium‐functionalized POM cluster, 1 is further composited with gold nanoparticles (NPs) to prepare 1 −Au NPs, which doubles the blood circulation time of 1 ‐based nanodrug. Efficient separation of photogenerated charges in 1 −Au NPs largely boosts the photothermal conversion efficiency (PCE = 55.0%), which is nearly 2.1 times that of either single 1 (PCE = 26.7%) or Au NPs (PCE = 26.2%), and simultaneously facilitate the generation of toxic activate reactive oxygen species in tumor microenvironment. Based on these findings, it is demonstrated that 1 −Au NPs are a multifunctional and renal clearable nanomedicine with great potential in photoacoustic imaging guiding photothermal–chemodynamic therapy for breast cancer.