Abstract
A new high performance fluorescence assay for detection of Ag+ based on CdS quantum dots (QDs) using L-Aspartic acid (L-Asp) as a stabilizer was proposed in this work. The CdS quantum dots conjugation with L-Aspartic acid (L-Asp@CdS QDs) were successfully synthesized via a simple hydrothermal process. The QDs have a fluorescence emission band maximum at 595 nm with a quantum yield of 11%. The obtained CdS QDs exhibit a particle size of 1.63 ± 0.28 nm and look like quantum dot flowers. Basically, the fluorescence intensity of L-Asp@CdS QDs can be enhanced only upon addition of Ag+ and a redshift in the fluorescence spectrum was observed. Under optimum conditions, the fluorescence enhancement of L-Asp@CdS QDs appeared to exhibit a good linear relationship in between 100–7000 nM (R2 = 0.9945) with the Ag+ concentration, with a detection limit of 39 nM. The results indicated that the L-Asp@CdS QDs were well used in detection for Ag+ as fluorescence probe in aqueous solution with high sensitivity and selectivity. Moreover, the sensing system has been applied in detection Ag+ in real water samples. The recovery test results were 98.6%~113%, and relative standard deviation (n = 5) is less than 3.6%, which was satisfactory.
Highlights
Semiconductor quantum dots (QDs) [1,2], whose size is less than the material Bohr exciton radius, have received more and more attention due to their size dependence and novel optical properties during the past decades
We studied fluorescent turn-on assay of Ag+ in aqueous solution based on L-Aspartic acid (L-Asp) functionalized CdS QDs, which were synthesized by a facile hydrothermal method
L-Aspartic acid capped CdS QDs were synthesized in aqueous solution using a simple method
Summary
Semiconductor quantum dots (QDs) [1,2], whose size is less than the material Bohr exciton radius, have received more and more attention due to their size dependence and novel optical properties during the past decades. Their three-dimensions confined to the nanoscales with a size typically in the range of 1–10 nm [1,3]. Organic molecules are selected as modifiers, which aim at reducing the surface defects and toxicity of semiconductor QDs. In recent years, surface functionalization and modification of QDs have widely applied as fluorescent probe in chemical and biological analysis [8,9,10,11,12]. The present fluorescent sensor system has been applied to the Ag+ determination in real water samples and the results are agreeable
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
