Fluorescence Determination of Merucury(II) Using a Thymine Aptamer
A label-free thymine-rich sequence and a molecular beacon were synthesized to construct a highly sensitive and selective fluorescence probe for the determination of mercury(II). The aptamer of the thymine-rich sequence selectively bonded with mercury(II) with an accompanying change in the fluorescence intensity of the molecular beacon due to the higher affinity of the aptamer with mercury(II). The limit of detection was 12.7 nanomolar, and a linear relationship was obtained between the fluorescence and mercury(II) concentrations up to 1 micromolar. The assay was highly selective for the mercury(II) and not significantly affected by other metal ions.
Abstract In the application of some polymers as track detectors, the attention should be paid to the fact that the track recording properties of these polymers are changed under the influence of certain parameters, such as the electromagnetic radiations and environmental conditions. In this work the etching effects of 60Co gamma irradiated CR-39 polycarbonate have been studied. For deeper study of the structural changes in CR-39, the FTIR and UV–visible spectra have been analyzed. The FTIR spectra shows considerable changes due to the gamma exposure. The contribution of degradation mechanism is discussed.