Construction of High-Sensitivity CdTe Quantum Dots as Fluorescence Probe and Its Interaction with Metal Ions

We used denatured bovine serum albumin (dBSA) to modify water-soluble CdTe quantum dots (QDs), constructed the metal ion probe with high detection sensitivity, and studied its detection performance and mechanism for heavy metal ions. Water-soluble CdTe quantum dots with a high quantum yield and thioglycolic acid(TGA) as stabilizer were synthesized by optimizing the reaction conditions. We used dBSA to modify the CdTe QDs of different sizes respectively, determined the optimum ratios of dBSA to QDs. And then the interaction between QDs and metal ions was studied after purifying the dBSA surface-modified QDs (dBSA-QDs). Experimental results showed that the conjugation of QDs by dBSA efficiently improved the photoluminescence quantum yield, the chemical stability of QDs and stability against photobleaching; meanwhile the fluorescence of dBSA-QDs can be quenched by heavy metal ions effectively, and the detection sensitivity was improved greatly compared with TGA-coated QDs.