Although Ag₂S quantum dots (QDs) have attracted extensive attention in the fields of diagnosis and therapy, it is still a challenge to prepare Ag₂S QDs with well-controlled size distribution. Herein, size-tunable Ag₂S QDs with glutathione (GSH) as ligands were prepared via a facile aqueous precipitation method. The QDs are precisely prepared through carefully controlled growth of Ag2S QDs by varying the heating time. Morphology and structure characterization verify that Ag₂S QDs with 2.0–5.8 nm in diameter are coordinated with GSH through thiol group. The as-prepared Ag₂S QDs exhibit broad absorption spectra and narrow fluorescence emission spectra in the near-infrared region. Meanwhile, the QDs perform excellent and stable photothermal effect with a photothermal conversion efficiency up to 58.6%. More importantly, it is found that the size of Ag₂S QDs has a significant influence on the fluorescence intensity and photothermal effect. The cell viability evaluation in vitro demonstrates that Ag₂S QDs have low cytotoxicity to 293 T cells and Hela cells by methyl thiazolyl tetrazolium test. This paper proposes a convenient route to prepare unique Ag₂S QDs, which are capable to act as ideal theranostics probes for photothermal therapy and simultaneously monitoring the therapeutic effect for effective cancer treatment.

尽管Ag ₂ S量子点(QDs)在诊断和治疗领域引起了广泛关注，但制备尺寸分布可控的Ag ₂ S量子点仍然是一个挑战。在此，以谷胱甘肽 (GSH) 作为配体的尺寸可调的 Ag ₂ S QD 通过简便的水相沉淀法制备。通过改变加热时间仔细控制 Ag2S QD 的生长，精确制备 QD。形态和结构表征证实，直径为 2.0-5.8 nm 的Ag ₂ S QD 通过硫醇基团与 GSH 配位。制备好的 Ag ₂S QD 在近红外区域表现出宽吸收光谱和窄荧光发射光谱。同时，量子点表现出优异且稳定的光热效应，光热转换效率高达58.6%。更重要的是，发现Ag ₂ S QDs的尺寸对荧光强度和光热效应有显着影响。体外细胞活力评估表明，通过甲基噻唑基四唑试验，Ag ₂ S QDs对293 T细胞和Hela细胞具有低细胞毒性。本文提出了一种制备独特的 Ag ₂ S QD的便捷途径，该方法能够作为理想的光热治疗诊断探针，同时监测有效癌症治疗的治疗效果。