A direct chemiluminescence method for the determination of nucleic acids has been developed based on the enhancement of nucleic acids on the chemiluminescence light emission of the reaction between Ru(phen)3 2+(phen=1,10-phenanthroline) and Ce(IV). Under the optimum conditions, the calibration graphs are linear in the range of 5.0

enhancement of citric acid on the chemiluminescence light emission of tris-(2,2%-bipyridine) ruthenium (II). In the presence of tris-(2,2%-bipyridine) ruthenium (II), upon the addition of Ce (IV), resulted in intense light emission. The emission intensity is greatly enhanced by the presence of citric acid. The linear range and detection limit of citric acid are 3.0×10-8～6.0×10-6mol l-1 and 3.0×10-8mol l-1, respectively. The precision of the proposed method is determined by analyzing 11 samples containing 1.0×10-7mol l-1 citric acid. The relative standard deviation is 3.0%. The enhanced mechanism of citric acid was studied. The method was evaluated by carrying out an nterference study with common ions and compounds, by a recovery study and by analysis of human urine and orange juice. A satisfactory result was obtained.

A time-resolved chemiluminescence method for the determination of oxalic and tartaric acid was developed. The method is based on the kinetic distinction of the chemiluminescent reaction of Ru(bipy)3 2+and oxalic and tartaric acid with CeIV. The oxalic acid system gives the highest chemiluminescence intensity at 2s, whereas the tartaric acid system gives its most intense chemiluminescence emission at 50s. Oxalic acid (1.4

Snmmary-A new reagent proflavine-N, N, N', N'-tetraacefic acid (PTA) synthesized in our laboratory has been found useful as a chemiluminescence reagent for the determination of ruthenium (Ru) in pH 2.5 sulfuric acid solution containing acetone, it can be oxidized catalytically by hydrogen peroxide. With Ru (III) as catalyst, it emits light selectively. The linear range is between 2.0

CdSe quantum dots (QDs) have been prepared and modified with mercaptoacetic acid. They are water-soluble and biocompatible. To improve their fluorescence intensity and stability in water solution, bovine serum albumin (BSA) was absorbed onto their surface. Based on the quench of fluorescence signals of the functionalized CdSe QDs in the 543nm wavelength and enhancement of them in the 570-700 nm wavelength range by Ag (I) ions at pH 5.0, a simple, rapid and specific method for Ag (I) determination was proposed. In comparison with single organic fluorophores, these nanoparticles are brighter, more stable against photobleaching, and do not suffer from blinking. Under the optimum conditions, the response is linearly proportional to the concentration of Ag (I) between 4.0