Electochemiluminescence of CdTe/CdS Quantum Dots with Triproprylamine as Coreactant in Aqueous Solution at a Lower Potential and Its Application for Highly Sensitive and Selective Detection of Cu²⁺

Abstract

Anodic electrochemiluminescence (ECL) of 3-mercaptopropionic acid (MPA)-capped CdTe/CdS core-shell quantum dots (QDs) with tripropylamine (TPrA) as the co-reactant were studied in aqueous (Tris buffer) solution for the first time. The results suggest that the oxidation of TPrA at a glassy carbon electrode (GCE) surface participated in the ECL of QDs, and the onset potential and the intensity of ECL of CdTe/CdS QDs were affected seriously by TPrA, as the co-reactant, in Tris buffer solution. The onset potential of ECL in this new system was about þ 0.5 V (vs. Ag/AgCl) and the ECL intensity greatly enhanced when TPrA was present. Various influencing factors, such as the electrolyte, pH, QDs concentration, potential range and scan rates on the ECL were studied. Based on the selective quenching by Cu 2þ to the light emission from CdTe/CdS QDs/TPrA system, a highly sensitive and selective method for the determination of Cu 2þ was developed. At the optimal conditions, the relative ECL intensity, I 0 /I, was proportional to the concentration of Cu 2þ from 14 nM to 0.21 mM with the detection limit of 6.1 nM based on the signal-to-noise ratio of 3. The possible ECL mechanism of QDs and the quenching mechanism of ECL were proposed.

Graphene oxide amplified electrochemiluminescence of graphitic carbon nitride and its application in ultrasensitive sensing for Cu2+

“…It has been reported that the ECL emission based on Cd-based semiconductors can be quenched statically by Cu 2+ . 28,29 In this work, to our best knowledge, the effective ECL quenching of the g-C 3 N 4 /GO system by trace amounts of Cu 2+ has never been reported before, demonstrating its potential application in Cu 2+ detecting. samples are directly added into 5 mL ECL cell for ECL measurement respectively.…”

Quantum dot-based photoelectric conversion for biosensing applications

“…ECL reactions can be classified into oxidative-reduction and reductive-oxidation, according to the generated intermediate species being reducing or oxidizing during an electrochemical process. In general, commonly-used ECL coreactants include oxalate (C 2 O 4 2-) [15], tri-n-propylamine (TPrA) [20], dibutylaminoethanol (DBAE) [21], and sulfite (SO 3 2-) [22], which belong to the ''oxidation-reduction'' reaction mechanism, and hydrogen-peroxide [24], and peroxydisulfate (S 2 O 8 2-) [25], which are "reductiveoxidative" coreactants. Table 1 shows the corresponding mechanisms of the "oxidation-reduction" reaction.…”

Electrochemiluminescent functional nucleic acids‐based sensors for food analysis

“…Embedded ECL reagents owning high affinity with dsDNA, Ru(phen) 3 2+ and Ru‐dppz, have been also employed to develop label‐free ECL sensors for Hg 2+ . Except for Pb 2+ and Hg 2+ , other heavy metal ions (Cu 2+ and Ag + ) were assayed using ECL FNA‐based sensors. In addition, the researchers also developed ECL sensors for simultaneous detection of multi metal ions…”