A fluorescence-electrochemical study of carbon nanodots (CNDs) in bio- and photoelectronic applications and energy gap investigation. Issue 30 (20th July 2017)

• Record Type: Journal Article
• Authors: Zeng, Zheng; Zhang, Wendi; Arvapalli, Durga M.; Bloom, Brian; Sheardy, Alex; Mabe, Taylor; Liu, Yiyang; Ji, Zuowei; Chevva, Harish; Waldeck, David H.; Wei, Jianjun
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 30(2017)
• Page Start: 20101
• Page End: 20109
• Publication Date: 2017-07-20
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c7cp02875j
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : A new perspective on the optoelectronic properties of CNDs is obtained from a novel fluorescence spectroelectrochemistry and comprehensive energy gap investigation. Abstract : Carbon nanodots (CNDs) have attracted great attention due to their superior solubility, biocompatibility, tunable photoluminescence, and opto-electronic properties. This work describes a new fluorescence-based spectroelectrochemistry approach to simultaneously study the photoluminescence and wavelength dependent photocurrent of microwave synthesized CNDs. The fluorescence of CNDs shows selective quenching upon a reversible redox couple, ferricyanide/ferrocyanide, reaction during cyclic voltammetry. The CND modified gold slide electrode demonstrates wavelength dependent photocurrent generation during the fluorescence-electrochemical study, suggesting the potential application of CNDs in photoelectronics. UV-Vis absorption and electrochemistry are used to quantify the energy gap of the CNDs, and then to calibrate a Hückel model for CNDs' electronic energy levels. The Hückel (or tight binding) model treatment of an individual CND as a molecule combines the conjugated π states (CC) with the functional groups (CO, C–O, and COOH) associated with the surface electronic states. This experimental and theoretical investigation of CNDs provides a new perspective on the optoelectronic properties of CNDs and should aid in their development for practical use in biomedicine, chemical sensing, and photoelectric devices.