Organic solvent effect on DAM and DAM–Hg2+ complex
Considering environmental applications, effect of MeCN volume fraction on I525 nm was also studied. The results ( Fig. 6) showed that fluorescence intensity (I525 nm) of the system increased with the increase of MeCN, no Phenformin with or without Hg2+. When the volume fraction of MeCN was lower than 0.5, the fluorescence intensity (I525 nm) of DAM is small, leading to a discount of fluorescence signals, which deserved our attention to elevate levels of organic solvent to enhance the fluorescence of DAM in the presence of Hg2+. However, the increase of organic solvent would restrict the application of DAM. As a matter of fact, the trend achieved from the plot demonstrated that an optimized aqueous solution HEPES (pH 7.5, 20 mM)–MeCN (2/8, v/v) showed a significantly fluorescence quenching with the addition of Hg2+ at room temperature.
Fig. 6. Fluorescence intensity changes of DAM (10.0 μM) and DAM–Hg2+ complex (100.0 μM) with respect to the volume ratio of acetonitrile and water (20 mM HEPES, pH = 7.5). λex = 335 nm, λem = 525 nm.Figure optionsDownload full-size imageDownload as PowerPoint slide