Simultaneous Fluorescence Detection of Mercury(Ⅱ) and Silver Ions Based on Rhodamine B Isothiocyanate and 5-Carboxyfluorescein-ss DNA Modified Probe

A new fluorescence sensor is developed for simultaneous detection of Hg~(2+) and Ag~+. During the detection process,Hg~(2+) forms complexes with the fluorescent dye rhodamine B isothiocyanate(RBITC) modified onto the surface of gold nanoparticles(Au NPs),resulting in RBITC's displacement from the surface of Au NPs and the recovery of fluorescence. Meanwhile,Ag~+ forms “C-Ag~+-C” complex with C-rich 5-carboxyfluorescein(FAM)-ss DNA modified onto the surface of Au NPs,which keeps the fluorescent dye FAM close to the Au NPs and results in quench of fluorescence. The experimental results show a wide linear range and a good sensitivity. The limit of detection is 1.06 nmol/L for Ag~+ and 0.48 nmol/L for Hg~(2+). This detection method is not only easy to operate but also efficient.

Simultaneous fluorescence detection of mercury (II) and silver ions based on rhodamine B isothiocyanate and 5-carboxyfluorescein-ssDNA modified probe

A new fluorescence sensor is developed for simultaneous detection of Hg²⁺ and Ag⁺. During the detection process, Hg²⁺ forms complexes with the fluorescent dye rhodamine B isothiocyanate (RBITC) modified onto the surface of gold nanoparticles(AuNPs), resulting in RBITC’s displacement from the surface of AuNPs and the recovery of fluorescence. Meanwhile, Ag⁺ forms “C-Ag⁺-C” complex with C-rich 5-carboxyfluorescein (FAM)-ssDNA modified onto the surface of AuNPs, which keeps the fluorescent dye FAM close to the AuNPs and results in quench of fluorescence. The experimental results show a wide linear range and a good sensitivity. The limit of detection is 1.06 nmol/L for Ag⁺ and 0.48 nmol/L for Hg²⁺. This detection method is not only easy to operate but also efficient.