Microwave Synthesis Of CdTe Quantum Dots And Its Application In Flow Injection Chemiluminescence

Semiconductor nanocrystals also called Quantum Dots (QDs) are comprised of II-VI and III-V group elements. Compared to traditional organic dyes,excitation spectrum of quantum dots is very wide;they have high photochemical stability, narrow and symmetric emission spectra,they also have size adjustable and other excellent features.CdTe nanocrystals (NCs) with dimercaptosuccinic acid (MSA) as stabilizer are prepared by simple microwave synthesis method in this paper. Microwave synthesis of CdTe nanoparticles with Dimercaptosuccinic acid as stabilizer has not yet been reported. By optimizing the experimental conditions (such as reactant ratios, microwave heating time,microwave heating temperature,pH and stabilizer),we synthesized a series of CdTe quantum dots having different fluorescence emission wavelength. The emission wavelength was continuously changed from 500 nm to 750 nm. The method of synthesis of quantum dots and full width at half maximum (FWHM) is relatively narrow having high luminous intensity.Flow injection chemiluminescence technique is combination of both flow injection analysis and chemiluminescence detection techniques used for highly sensitive of trace analysis. The technology has high analysis throughput,relatively simple equipment,without background interference from scattered light. It is is widely used analytical protocol in variety of food,pharmaceutical analysis fields.CdTe quantum-dots (CdTe-QDs) of different sizes and capped with dimercaptosuccinic acid were prepared by the microwave irradiation method. The CdTe-QDs can significantly enhance the chemiluminescence (CL) of the pyrogallol-H₂O₂-Cr³⁺ system. Those with a diameter of 3.8 nm produce the most intensive CL.UV-vis,photoluminescence (PL) spectra and CL spectra were acquired in order to explore the effect.Cr³⁺ was detected in the concentration range of 20 pmol/L– 30μmol/Lwith linear regression equation of I= 157 + 14logC with R = 0.998. Limit of detection (3σ) is 6 pmol/L,with relative standard deviation (n = 11) of 1.7%.And a continuous flow injection CL method was developed and applied to the determination of Cr³⁺ in tap water and lake water samples with satisfactory results.