Matulionytė Marija, Marcinonytė Raminta, Rotomskis Ričardas
National Cancer Institute, Biomedical Physics Laboratory, P. Baublio Street 3b, LT-08406 Vilnius, LithuaniabVilnius University, Biophotonics Group of Laser Research Centre, Sauletekio Avenue 9, LT-10222 Vilnius, Lithuania.
National Cancer Institute, Biomedical Physics Laboratory, P. Baublio Street 3b, LT-08406 Vilnius, Lithuania.
J Biomed Opt. 2015 May;20(5):051018. doi: 10.1117/1.JBO.20.5.051018.
Ultrasmall photoluminescent gold nanoclusters (Au NCs), composed of several atoms with sizes up to a few nanometers, have recently stimulated extensive interest. Unique molecule-like behaviors, low toxicity, and facile synthesis make photoluminescent Au NCs a very promising alternative to organic fluorophores and semiconductor quantum dots (QDs) in broad ranges of biomedical applications. However, using gold nanoparticles (Au NPs) for bioimaging might cause their degradation under continuous excitation with UV light, which might result in toxicity. We report spectral changes of photoluminescent 2-(N-morpholino) ethanesulfonic acid (MES)-coated (Au-MES) NCs under irradiation with UV/blue light. Photoluminescent water soluble Au- MES NCs with a photoluminescence (PL) band maximum at 476 nm (λex = 420 nm) were synthesized. Under irradiation with 402 nm wavelength light the size of photoluminescent Au-MES NCs decreased (λem = 430 nm). Irradiating the sample solution with 330 nm wavelength light, nonluminescent Au NPs were disrupted, and photoluminescent Au NCs (λem = 476 nm) were formed. Irradiation with 330 nm wavelength light did not directly affect photoluminescent Au-MES NCs, however, increase in PL intensity indicated the formation of photoluminescent Au NCs from the disrupted nonluminescent Au NPs. This study gives a good insight into the photostability of MES-coated Au NPs under continuous excitation with UV/blue light.
超小光致发光金纳米团簇（Au NCs）由几个原子组成，尺寸可达几纳米，最近引起了广泛关注。独特的分子样行为、低毒性和简便的合成方法使光致发光Au NCs在广泛的生物医学应用中成为有机荧光团和半导体量子点（QDs）非常有前景的替代品。然而，使用金纳米颗粒（Au NPs）进行生物成像可能会导致它们在紫外光连续激发下降解，这可能会导致毒性。我们报告了光致发光的2-（N-吗啉代）乙磺酸（MES）包覆的（Au-MES）NCs在紫外/蓝光照射下的光谱变化。合成了在476 nm（λex = 420 nm）处具有最大光致发光（PL）峰的水溶性光致发光Au-MES NCs。在402 nm波长光照射下，光致发光Au-MES NCs的尺寸减小（λem = 430 nm）。用330 nm波长光照射样品溶液，非发光的Au NPs被破坏，形成了光致发光的Au NCs（λem = 476 nm）。用330 nm波长光照射不会直接影响光致发光的Au-MES NCs，然而，PL强度的增加表明从被破坏的非发光Au NPs形成了光致发光的Au NCs。这项研究很好地洞察了MES包覆的Au NPs在紫外/蓝光连续激发下的光稳定性。
