Ultrasensitive Pb2+ detection based on fluorescence resonance energy transfer (FRET) between quantum dots and gold nanoparticles.
Positively charged CdTe-QDs capped with cysteamine (CA-CdTe-QDs) and negatively charged AuNPs capped with 11-mercaptoundecanoic acid (MUA-AuNPs) have been prepared. They are water-soluble and biocompatible. An assay for the determination of Pb2+ has been proposed based on the modulation in FRET efficiency between QDs and AuNPs in the presence of Pb2+, which inhibits the interaction of the QD-AuNP assembly. This method is easy to operate and with remarkably high sensitivity. Under the optimum conditions, the response is linearly proportional to the concentration of Pb2+ in the range 0.22-4.51 ppm, and the detection limit is found to be 30 ppb of Pb2+ due to the superior fluorescence properties of QDs. The mechanism of this strategy is also discussed.
Wang
Xin
X
The MOE Key Laboratory of Analytical Science and the Key laboratory for Chemical Biology of Fujian Province, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Guo
Xiangqun
X
D000042:Absorption; D019187:Cadmium Compounds / Q000737:chemistry; D003543:Cysteamine / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D045663:Quantum Dots; D055672:Static Electricity; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry
C505222:11-mercaptoundecanoic acid; D019187:Cadmium Compounds; D005227:Fatty Acids; D013438:Sulfhydryl Compounds; D007854:Lead; D003543:Cysteamine; D006046:Gold; D013691:Tellurium; C028337:cadmium telluride