Abstract

Polydiacetylene (PDA)-based liposome have been attractive as sensory platforms owing to their applicability in simultaneous detection of colorimetric and fluorogenic signals. As PDA show low quantum yield, gold nanoparticles (GNPs) were used to amplify the fluorescence of the PDA by localized surface plasmon resonance. In this study, positively and negatively surface charged GNPs at different concentrations were complexed with negatively charged PDA liposome (GNP/PDA). Positively charged GNPs caused tight binding at the surface of negatively charged PDA liposome, became aggregated due to colloidal instability and thereby dramatically quenched the fluorescence of PDA. While negatively charged GNPs sparsely placed on the surface of the PDA liposome, at the optimized complexing condition, generated ∼10%of fluorescence amplification compared to non-complexed PDA liposome as observed by the photoluminescence spectra of the stable colloids. Under the optimum incubation conditions, GNP/PDA liposome that specifically binds with Pb²⁺via its phenolic group, exhibited increased fluorescence intensity compared to the non-complexed PDA liposome-at the same concentration of target Pb²⁺.

摘要

由于基于聚二乙炔（PDA）的脂质体可同时检测比色和荧光信号，因此作为传感平台具有吸引力。由于PDA显示出较低的量子产率，因此使用金纳米颗粒（GNP）通过局部表面等离子体激元共振来放大PDA的荧光。在这项研究中，将具有不同浓度的带正电荷和带负电荷的表面GNP与带负电荷的PDA脂质体（GNP / PDA）复合。带正电的GNP导致带负电的PDA脂质体表面紧密结合，由于胶体不稳定性而聚集，从而显着淬灭PDA的荧光。当带负电荷的GNP稀疏地放置在PDA脂质体的表面上时，在优化的复合条件下，稳定胶体的光致发光光谱表明，与非复合PDA脂质体相比，其产生的荧光放大率约为10％。在最佳孵育条件下，与Pb特异性结合的GNP / PDA脂质体与非复合PDA脂质体相比，在相同浓度的目标Pb ^2+下，2 ⁺通过其酚基团表现出增强的荧光强度。