| two parts, review and research report. were included in this thesis.A review of progress and application of nucleic acid was given with 67references in the first part. The method and the principle for setup nucleic acidsensors was also given. Nucleic acid was classified into three groups basedon the method of determination.The research report is focused on the study of a novel electrochemilum-lnescence(ECL) system and a novel chemiluminesconc(CL) system. The appl-ication of this two systems were also involved.It was firstly founded that fluorescein, 2,7-dichloroflurescein, tetrabromo-nuorescein and tetrachlorotetraiodofluorescein produced electrochemiluminescen-ce on the surface of platinum anode in the prescence of sodium hydroxide,their ECL properties including the effect of potential and PH, ECL spectrumand fluorescence spectrum, the effect of surfactant were studied. The mech-anistn of ECL was concluded as follow, the dissolved oxygen reacted withOH-on the surface of anode and produced O2. O2 reacted with fluoresceinand gave energy, the energy excitated fluorescein molecules to excitated state,then the excitated state molecules gave emission when it came back to groundstate. The cetyltrimethylammonium bromide(CTMAB) micelle supported a mic-roenviroment which was .benefit to keep a longer life time of excitated molec-ules. Certain metal ions were exaxnined respectively to see any enhancementor quenching to this ECL system, it wes found that only the copper ioncould enhence the ECL. Above ECL system was applied to determinc themetabolic process of copper in rabbit blood coupling with microdialysis andrealized near realtime determination. Electrochemical preconcentrationtechnique was involved to eliminate the intefference may be caused byingredients in serum and to improve the selectivity. This method reached asatisfied result with prominent selectivity.It was found that ascorbic acid could react with the 1nixture so1ution of'. fiuotescein, cetyltrimethylammonium bromide(CTMAB) and copper ion(lI ). andproduced chemiluminescence emission in alkaline solution. pel1ydroascorbicacid and other reducers such as uric acid, glucose and sodium su1fiIe eitherdid not give any emission or quenched qhemiluminescence. The mechanismwas proposed to be that nuorescein moiecuie was oxidized to an oxidationproduct, this intermediate product reacted with ascorbic acid through ahydrogen transport process and gave emission. As an application of abovechemiluminescence system, a simple and robust ascorbic acid detcrminationmethod was setup, and was appIied to tablet 4issolution testing with reIative1ysimple equipment and automatic operation. FiltIation and flow injection wereused for sampling frOm the dissolution media, the sampling ffequency was240h-', andthe assay thequ-ency was 60h-'. The response of this method tothe concentration of ascorbic acid .was linear in the range of 5-l20ppm,obeyed' an equation expressed as y=3.475lx-10.055(n=6).rv0.9949.(n= 1 l,25ppm ascorbic acid).A new chemiluminescence system of fluorescein, CTMA8 and copper (l1)miAnreacting with ascorbic acid was successfully applied to determinc uricacid inurine with good selectivity. The sensihvity fOr uric acid analysis in.unne was optimized. Flow injection was involved in this woth and an easyoperating analysis syStem without pre-separahon was setup. The calibration1inear range was 0 -- l0 mgL-', obeyed equation I= -306.58 c + 3557.9 (n==5,re0.98l); RSD=1.2% (n==1l). This method has been successfully applied to thedeteednationof uric acid in chne samples. |
PDF Full Text Request