Application And Studies On Water-soluble CdTe Quantum Dots For Pharmaceutical Analysis And Metal Ions Detection

Recently, semiconductor quantum dots (QDs) have been widely applied in several fields such as medicament chemistry, biochemistry and so on because of its unique optical properties. In this paper, we deal with the preparation of high fuorescence QDs and used as luminescent sensor for the determination of some drug molecules and metal ions. The main results are outlined as followings:1. A novel method for determination of aminophylline has been developed based on enhancement of the fluorescence of CdTe QDs by aminophylline in aqueous solutions. Under optimum conditions, the relative fluorescence intensity of CdTe QDs is linearly proportional to aminophylline concentration from2.00to80.0μg ml-1with a correlation coefficient of0.9979for aminophylline determination and a detection limit of0.531μg ml-1.The proposed method has been applied to the determination of aminophylline in tablets and injection samples with the recoveries reaching93%107%.2. A novel method for determination of tobramycin has been developed based on enhancement of the fluorescence of CdTe QDs by tobramycin in aqueous solutions. It can perform accurate and simple determination of tobramycin concentration in samples with satisfactory results.Under optimum conditions, the relative fluorescence intensity of CdTe QDs is linearly proportional to tobramycin concentration from0.05μg mL-1to1.2μg mL-1with a correlation coefficient of0.9987for tobramycin determination and a detection limit of0.018μg ml-1.The proposed method has been applied to the determination of tobramycin in samples with the recoveries reaching94%～107%.3. A novel method is used for the determination of doxycycline (DOX) and terramycin (OTC) has been developed based on quenching of the fluorescence of CdTe QDs by DOX and OTC in aqueous solutions. Under the optimum conditions, the fluorescence signal of the TGA-capped CdTe QDs is significantly quenched with increasing DOX and OTC concentration, and there is a good linear relationship between relative fluorescence intensity and the concentration of DOX and OTC in the range0.2～40.0and0.4～20.0μg mL-1with a correlation coefficient(R) of0.9974and0.9971.The detection limit was0.077and0.092μg mL-1. The method has many advantages over some common methods, such as simple, rapid and wide linear range, etc. As an application, the proposed method was successfully applied to the analysis of DOX and OTC in tables with the recoveries reaching95%-104%and94%～105%.4. A spectrofluorimetric method for the determination of Fe2+has been developed based on quenching of the fluorescence of TGA-capped CdTe quantum dots by Fe2+in aqueous solutions. It can perform accurate, simple and highly sensitive determination of Fe2+concentration in water samples. Under optimum conditions, the quenched fluorescence intensity increased linearly with the concentration of Fe2+ranging from5.0×10-8and4.0×10-6mol L"1with a correlation coefficient of0.9969.The limit of detection for Fe2+was found to be1.2x10-8mol L-1. As an application, the proposed method was successfully applied to the analysis of Fe2+in mineral water and synthetic samples, and the results were satisfactory.