Quartz/APES

Rhodamine B 67 is frequently used in the quantitative determination of DNA or RNA and fluorescent labeling for DNA [190-192]. This dye was assembled onto the surface of a quartz substrate by electrostatic interaction between the fluorescence reagent RB and y-aminopropyltriethoxysilane (APES), and the Quartz/ APES/RB film was constructed (Fig. 1) [193]. 

Fluorescence studies and the binding interaction of Quartz/APES/RB with single- and double-stranded oligonucleotides (ssDNA and dsDNA) in Tris-HCl buffer solution of pH 7.4 were carried out. Quartz/APES/RB exhibited emission at 576 nm, whereas Quartz/APES without BB where nonfluorescent, suggesting that RB successfully assembled on the surface of quartz wafers. By comparison with Aem of 5 x 10 5 M RB solution, which was 588 nm, a hypsochromic shift was found. Considering the fluorescence microscopical image of Quartz/APES/RB, it... 

Overall, Quartz/APES/RB allowed for extremely high sensitive fluorescence recognition for ssDNA and dsDNA with the detection limit of 2.4 ngL 1 and 0.85 ngL-1, respectively. 

Tang AXJ, Pravda M, Guilbault GG, Piletsky S, and Turner APE. Immunosensor for okadaic acid using quartz crystal microbalance. Anal. Chim. Acta 2002 471 33 0. 

---