Quantum Dot Electrochemiluminescence in Aqueous Solution at Lower Potential and Its Sensing Application

Abstract

The unique strategy for electrochemiluminescence (ECL) sensor based on the quantum dots (QDs) oxidation in aqueous solution to detect amines is proposed for the first time. Actually, there existed two QDs ECL peaks in anhydrous solution, one at high positive potential and another at high negative potential. However, here we introduced the QDs oxidation ECL in aqueous solution to fabricate a novel ECL sensor. Such sensor needed only lower positive potential to produce ECL, which could prevent the interferences resulted from high potential as that of QDs reduction ECL in aqueous solution. Therefore, the present work not only extended the QDs oxidation ECL application field from anhydrous to aqueous solution but also enriched the variety of ECL system in aqueous solution. Furthermore, we investigated the QDs oxidation ECL toward different kinds of amines, and found that both aliphatic alkyl and hydroxy groups could lead to the enhancement of ECL intensity. Among these amines, 2-(dibutylamino)ethanol (DBAE) is the most effective one, and accordingly, the first ECL sensing application of the QDs oxidation ECL toward DBAE is developed; the as-prepared ECL sensor shows wide linear range, high sensitivity, and good stability.

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+

“…The current-time curves and the corresponding ECL intensities were shown in Figure 4B. It can also be seen that the onset potential of ECL was about þ 0.5 V which was lower than that reported previously at positive potential region [13,14,18] and the ECL intensity was increased with the increasing of potential.…”

“…Because the anodic ECL of QDs was very weak at low concentration and the onset potential was more positive, it is difficult to detect the quenching ECL of QDs at commercial conventional electrode surface. Therefore, great efforts have focused on reducing the anodic ECL potential [15,16] and enhancing the anodic ECL intensity of QDs [17,18]. Ju and co-workers reported a sulfite-enhanced anodic ECL of MPA-modified CdTe QDs at þ 0.89 V in air-saturated aqueous solution [17].…”

“…Ju and co-workers reported a sulfite-enhanced anodic ECL of MPA-modified CdTe QDs at þ 0.89 V in air-saturated aqueous solution [17]. Dong and co-workers reported that the 2-(dibutylamino) ethanol (DBAE) could greatly enhance the ECL signal of CdTe at þ 0.9 V in aqueous solution [18]. TPrA was widely used as a co-reactant in the anodic ECL of Ru(bpy) 2þ 3 -TPrA system [19 -22].…”

ECL Luminophores

“…Usually, hydrogen peroxide or peroxydisulfate are used as coreactants at high potentials to generate semiconductor NP ECL. While in recent years amines such as DBAE are found to be used as coreactant with semiconductor NPs to generate strong ECL at low potential [102]. Furthermore, it was also discovered that DBAE, a tertiary amine, is the most effective one.…”

Lumineszierende Kohlenstoff‐Nanopunkte: Nanolichtquellen mit Zukunft

“…Da Halbleiter-Nanokristalle bekanntermaßen Elektrochemilumineszenz (ECL) zeigen, [38,39] ist es nicht weiter überraschend, dass auch C-Punkte für ECL-Studien von Interesse sind. [18,20] Die ECL-Emission von ca.…”