title: Enhanced electrogenerated chemiluminescence of tris(2,2'-bipyridyl)ruthenium(II) system by l-cysteine-capped CdTe quantum dots and its application for the determination of nitrofuran antibiotics.
abstract: This paper reports a new approach to enhance the electrogenerated chemiluminescence (ECL) of the tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3(2+)) system using resonance energy transfer with l-cysteine-capped cadmium telluride quantum dots (CdTe-QDs) in aqueous solution. The oxidative peak signal of Ru(bpy)3(2+) occurred at a voltage of 1.10V when the potential was cycled between 0.4 and 1.6V using cyclic voltammetry with a carbon screen-printed electrode (SPE) in a 0.11M phosphate buffer at pH 7.50. The l-cysteine-capped CdTe-QDs were synthesized and added into the solution of Ru(bpy)3(2+) to magnify the ECL signal. The ECL emission signal was investigated and the extreme enhancement of the ECL intensity was achieved due to the energy transfer by the l-cysteine-capped CdTe-QDs. It was found that the induced ECL from the Ru(bpy)3(2+) CdTe-QDs system was inhibited by the presence of selected nitrofurans. This quenching effect of nitrofuran antibiotics on the anodic ECL of Ru(bpy)3(2+) CdTe-QDs was found to be selective and concentration dependent and was observed to have a linear relationship over the concentration range 10-100×10(-6)M. The detection limits were found to be 0.40, 0.73 and 0.60µM for furaltadone (FTD), furazolidone (FZD) and nitrofurantoin (NFT). In addition, the proposed ECL method was successfully applied to detect the total residuals of selected nitrofuran residues in animal feed samples with satisfactory results.
authors.affiliation: Department of Chemistry, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand.
authors.forename: Narin
authors.initials: N
authors.lastname: Taokaenchan
authors.affiliation: Department of Chemistry, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand.
authors.forename: Tanin
authors.initials: T
authors.lastname: Tangkuaram
authors.affiliation: Department of Chemistry, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand.
authors.forename: Pusit
authors.initials: P
authors.lastname: Pookmanee
authors.affiliation: Department of Chemistry, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand.
authors.forename: Sirirat
authors.initials: S
authors.lastname: Phaisansuthichol
authors.affiliation: Department of Chemistry, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand.
authors.forename: Surasak
authors.initials: S
authors.lastname: Kuimalee
authors.affiliation: Department of Chemistry, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand. Electronic address: sakchais@mju.ac.th.
authors.forename: Sakchai
authors.initials: S
authors.lastname: Satienperakul
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification*; D015374:Biosensing Techniques / Q000379:methods*; D003545:Cysteine / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods; D005504:Food Analysis; D049449:Luminescence; D009581:Nitrofurans / Q000302:isolation & purification*; D009942:Organometallic Compounds; D045663:Quantum Dots / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D009581:Nitrofurans; D009942:Organometallic Compounds; C415768:tris(2,2'-bipyridyl)ruthenium(II); D003545:Cysteine
keywords: CdTe quantum dots; Electrogenerated chemiluminescence; Nitrofurans