Thomas Telna, Sarangi Bibhu Ranjan, Sen Mojumdar Supratik
Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad 678 557, Kerala, India.
Department of Physics, Indian Institute of Technology Palakkad, Palakkad 678 557, Kerala, India.
ACS Omega. 2023 Apr 12;8(16):14630-14640. doi: 10.1021/acsomega.3c00462. eCollection 2023 Apr 25.
Atomically precise metal nanoclusters capped with small molecules like amino acids are highly favored due to their specific interactions and easy incorporation into biological systems. However, they are rarely explored due to the challenge of surface functionalization of nanoclusters with small molecules. Herein, we report the synthesis of a green-emitting (λ = 380 nm, λ = 500 nm), single-amino-acid (l-tryptophan)-scaffolded copper nanocluster (Trp-Cu NC) via a one-pot route under mild reaction conditions. The synthesized nanocluster can be used for the rapid detection of a heavy metal, silver (Ag(I)), in the nanomolar concentration range in real environmental and biological samples. The strong green photoluminescence intensity of the nanocluster quenched significantly upon the addition of Ag(I) due to the formation of bigger nanoparticles, thereby losing its energy quantization. A notable color change from light yellow to reddish-brown can also be observed in the presence of Ag(I), allowing its visual colorimetric detection. Portable paper strips fabricated with the Trp-Cu NC can be reliably used for on-site visual detection of Ag(I) in the micromolar concentration range. The Trp-Cu NC possesses excellent biocompatibility, making it a suitable nanoprobe for cell imaging; thus, it can act as an in vivo biomarker. The nanocluster showed a significant spectral overlap with anticancer drug doxorubicin and thus can be used as an effective fluorescence resonance energy transfer (FRET) pair. FRET results can reveal important information regarding the attachment of the drug to the nanocluster and hence its role as a potential drug carrier for targeted drug delivery within the human body.
由氨基酸等小分子包覆的原子精确金属纳米团簇因其特定的相互作用以及易于融入生物系统而备受青睐。然而，由于纳米团簇与小分子进行表面功能化存在挑战，它们很少被研究。在此，我们报道了在温和反应条件下通过一锅法合成一种发射绿色荧光（λ = 380 nm，λ = 500 nm）、以单一氨基酸（L-色氨酸）为支架的铜纳米团簇（Trp-Cu NC）。所合成的纳米团簇可用于在实际环境和生物样品中快速检测纳摩尔浓度范围内的重金属银（Ag(I)）。由于形成了更大的纳米颗粒，纳米团簇强烈的绿色光致发光强度在加入Ag(I)后显著猝灭，从而失去其能量量子化。在Ag(I)存在的情况下，还可以观察到从浅黄色到红棕色的明显颜色变化，从而实现其可视化比色检测。用Trp-Cu NC制作的便携式纸条可可靠地用于现场可视化检测微摩尔浓度范围内的Ag(I)。Trp-Cu NC具有优异的生物相容性，使其成为细胞成像的合适纳米探针；因此，它可以作为体内生物标志物。该纳米团簇与抗癌药物阿霉素显示出显著的光谱重叠，因此可作为有效的荧光共振能量转移（FRET）对。FRET结果可以揭示有关药物与纳米团簇结合的重要信息，从而揭示其作为人体内靶向药物递送潜在药物载体的作用。
