Nguyen Phuong-Diem, Nguyen Dung Thi Xuan, Son Sang Jun, Min Junhong
J Nanosci Nanotechnol. 2014 Nov;14(11):8719-23. doi: 10.1166/jnn.2014.9974.
This study described a novel fabrication of fluorescence co-encapsulating silica nanotubes (F@SNT) and the further application of the as-synthesized nanostructure as a ratiometric pH sensor in buffer solution. Silica nanotubes (SNTs) embedded anodic alumina oxide (AAO) template was fabricated by sol-gel technique, tetramethyl rhodamine (TMR-the reference dye) was incorporated directly onto silica layer via hydrophobic interaction. Subsequently, fluorescent isothiocyanate (FITC-pH sensitive dye) was encapsulated inside poly-dimethylsiloxane (PDMS) matrix and the FITC-PDMS nanocomposite was doped into the hollow structure of SNT using nano-molding lithography. On removing AAO, free-standing SNTs were obtained and were subsequently applied as a ratiometric pH sensor in phosphate buffer solution. The dual dye-doped SNTs showed excellent fluorescence and a good pH sensing performance from pH 5.2-8.0. The results were distinguishable by the emission spectra and by fluorescent visualization. High photostability, sensitivity, biocompatibility with adjustable sizes make dual dye doped-SNT a promising nanostructure for bioapplications.
本研究描述了一种新型的荧光共包封二氧化硅纳米管（F@SNT）的制备方法，以及所合成的纳米结构作为缓冲溶液中比率型pH传感器的进一步应用。通过溶胶-凝胶技术制备了嵌入阳极氧化铝（AAO）模板的二氧化硅纳米管（SNTs），四甲基罗丹明（TMR-参比染料）通过疏水相互作用直接掺入二氧化硅层。随后，将荧光异硫氰酸酯（FITC-pH敏感染料）包封在聚二甲基硅氧烷（PDMS）基质中，并使用纳米模塑光刻技术将FITC-PDMS纳米复合材料掺杂到SNT的中空结构中。去除AAO后，得到独立的SNTs，并随后将其用作磷酸盐缓冲溶液中的比率型pH传感器。双染料掺杂的SNTs在pH 5.2 - 8.0范围内表现出优异的荧光和良好的pH传感性能。通过发射光谱和荧光可视化可以区分结果。高光稳定性、灵敏度、可调节尺寸的生物相容性使双染料掺杂的SNT成为一种有前途的生物应用纳米结构。
