Electrochemistry of CdSe Quantum Dots Studied by Single Molecule Spectroscopy. Issue 6 (19th March 2019)

• Record Type: Journal Article
• Authors: Alshalfouh, Abdallatif; Oezaslan, Mehtap; Dosche, Carsten; Wittstock, Gunther
• Is Part Of: ChemElectroChem. Volume 6:Issue 6(2019)
• Page Start: 1884
• Page End: 1893
• Publication Date: 2019-03-19
• Subjects: quantum dots -- CdSe/CdS -- fluorescence correlation spectroscopy -- semiconductor electrochemistry -- nanoparticles; Electrochemistry -- Periodicals; 541.37
• DOI: 10.1002/celc.201801793
• Languages: English
• ISSNs: 2196-0216

Abstract

Abstract: In the last decades, nanoparticles (NPs) have emerged as active materials for various technically relevant processes like photochemistry, electrochemistry, and catalysis. Although numerous studies have been reported on the redox chemistry and electrochemistry of semiconductor NPs (quantum dots, QDs), the dynamics and kinetics of individual QDs at electrode surfaces are still poorly understood to date. In order to obtain more detailed information, the electrochemical reactivity of single CdSe/CdS QDs with negative surface charge has been investigated in this work on a platinum (Pt) microelectrode using fluorescence correlation spectroscopy (FCS). The results show that QDs are irreversibly oxidized in aqueous solution. However, the correlation time and average number of particles retrieved from FCS suggest that the QDs do not lose their emissive properties in a single collision and desorb from the electrode surface without being decomposed significantly. Abstract : One at a time : Single collision experiments with CdSe/CdS quantum dots at Pt microelectrodes are observed by using correlation time and average particle numbers extracted from fluorescence correlation spectroscopy data obtained from a volume directly adjacent to the electrode. The data show that the quantum dots retain their emissive properties after individual collision, electron transfer, and desorption from the electrode surface.