Abstract
A high performance fiber-optic sensor for Cu 2+ ions is proposed based on monodispersed hydrophobic CdSe/ZnS nanoparticles encapsulated within a silica shell and immobilized on the tip of an optical fiber by a polyvinyl alcohol (PVA) polymer coating. The experimental results show that the core-shell CdSe/ZnS@SiO 2 nanostructure exhibits a strong reduction in luminescence intensity following interaction with Cu 2+ ions. The porous silica shell of the nanostructure also plays a key role in the fluorescence quenching process by preventing the aggregation of the CdSe/ZnS nanoparticles; thereby promoting the adsorption of the Cu 2+ ions. There were linear relationships between the relative fluorescence intensity (I 0/I) and the concentration for Cu 2+ ions from 0 to 10 μM (R 2 = 0.9858). The resolution of this sensor detected by a commercial hand-held spectrometer was about 0.9 μM and therefore it is an ideal solution for applications in chemical and medical detections. The use of a silica-coated CdSe/ZnS QD has a number of key advantages as compared to the organic ligand modified QDs, including better selectivity, higher sensitivity, better chemical stability, and more stable with wide pH value.
Original language | English |
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Pages (from-to) | 119-125 |
Number of pages | 7 |
Journal | Sensors and Actuators, B: Chemical |
Volume | 165 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2012 Apr |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry