Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, China.
College of Pharmaceutical Sciences, Southwest University , Chongqing 400715, China.
Anal Chem. 2017 Feb 7;89(3):1808-1814. doi: 10.1021/acs.analchem.6b04124. Epub 2017 Jan 23.
Plasmonic resonance energy transfer (PRET), which occurs between the plasmonic nanoparticles and organic dyes, has significant potential in target sensing chemistry owing to its sensitivity at the single nanoparticle level. In this contribution, by using AuNPs, which has localized surface plasmonic resonance light scattering (LSPR-LS) around 550 nm, as the donor of PRET, a general sensitive detecting strategy of ions were developed. Targets can specifically react with a ring-close structured rhodamine spirolactam, which was prepared from rhodamines in the presence of different primary amine wherein the option of the primary amine is up to the targets, forming ring-open structured rhodamine spirolactam with the strong absorption around 550 nm. This process triggered the PRET from gold nanoparticles (AuNPs) to the ring-open structured rhodamine spirolactam. As a proof of concept, Cu and Hg were detected by using rhodamine B hydrazide and N-(rhodamine B)lactam-ethylenediamine, respectively. With the aid of a dark field microscope, the LSPR-LS of AuNPs gets decreased within 10 min with the addition of Cu or Hg. The scattering light spectra get red-shifted during the targets addition due to the quenching dip phenomenon. Further theoretical simulation indicated the PRET process could be aroused by the electric field diminishment of AuNPs via the interaction of rhodamine. This single nanoparticle based detecting strategy could be further applied for other anions, cations, or small organic molecules detection by simply changing the rhodamine spirolactam.
等离子体激元共振能量转移（PRET）发生在等离子体纳米粒子和有机染料之间，由于其在单个纳米粒子水平上的灵敏度，在目标感应化学中具有重要的应用潜力。在本研究中，通过使用金纳米粒子（AuNPs）作为 PRET 的供体，AuNPs 具有约 550nm 的局域表面等离子体共振光散射（LSPR-LS），开发了一种通用的离子敏感检测策略。目标物可以特异性地与环闭结构的罗丹明螺环酰胺反应，该螺环酰胺是由罗丹明在不同伯胺的存在下制备的，其中伯胺的选择取决于目标物，形成具有约 550nm 强吸收的开环结构罗丹明螺环酰胺。这个过程触发了从金纳米粒子（AuNPs）到开环结构罗丹明螺环酰胺的 PRET。作为概念验证，分别使用罗丹明 B 酰肼和 N-（罗丹明 B）内酰胺-乙二胺检测 Cu 和 Hg。借助暗场显微镜，在加入 Cu 或 Hg 后，AuNPs 的 LSPR-LS 在 10 分钟内降低。由于猝灭峰现象，添加目标物时散射光光谱发生红移。进一步的理论模拟表明，通过罗丹明的相互作用，可以通过 AuNPs 电场的减小来引发 PRET 过程。这种基于单个纳米粒子的检测策略可以通过简单地改变罗丹明螺环酰胺进一步应用于其他阴离子、阳离子或小分子的检测。
