State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, P. R. China.
ACS Appl Bio Mater. 2021 Mar 15;4(3):2790-2797. doi: 10.1021/acsabm.1c00011. Epub 2021 Feb 17.
Fluorescent gold nanoclusters with unique luminescence properties have drawn great attention in bioimaging. The gold nanoclusters with controlled multicolor fluorescence may benefit accurate fluorescence imaging. In this work, gold-nanocluster-engineered spiropyran ligands (AuNC-SP) were reported to achieve controlled dual-color imaging under single excitation. Through switching the Förster resonance energy transfer from the gold nanocluster segment to the open-ring state merocyanine by UV-vis irradiation, AuNC-SP possesses reversibly dual-color fluorescence. After AuNC-SP combined with chitosan to form AuNC-SP@CS nanoparticles, the steric protection of chitosan largely improved the oxidative stability of AuNC-SP upon UV irradiation. Moreover, the AuNC-SP@CS could be internalized within cancer cells and released AuNC-SP that further underwent transportation into the nucleus. Thus, the AuNC-SP@CS exhibits excellent and reversible dual-color fluorescence to label not only the cytoplasm but also the nucleus. We envisage the AuNC-SP@CS as an ideal probe for fine subcellular assays in the cell interior.
具有独特发光性质的荧光金纳米簇在生物成像中引起了极大的关注。具有可控多色荧光的金纳米簇可能有利于精确的荧光成像。在这项工作中，报告了金纳米簇工程化螺吡喃配体（AuNC-SP），可在单一激发下实现可控的双色成像。通过紫外光照射将金纳米簇段的Förster 共振能量转移到开环状态的硫靛，AuNC-SP 具有可逆的双色荧光。AuNC-SP 与壳聚糖结合形成 AuNC-SP@CS 纳米粒子后，壳聚糖的空间位阻大大提高了 AuNC-SP 在紫外光照射下的氧化稳定性。此外，AuNC-SP@CS 可以被内化到癌细胞内，并释放进一步运输到细胞核内的 AuNC-SP。因此，AuNC-SP@CS 表现出优异且可逆的双色荧光，不仅可以标记细胞质，还可以标记细胞核。我们设想 AuNC-SP@CS 作为细胞内精细亚细胞分析的理想探针。
