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Influence of Quantum Dot Surface on Electrochemical DNA Sensing Mechanism
Author(s) -
Fuku Xolile,
Baker Priscilla,
Iwuoha Emmanuel
Publication year - 2020
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201902079
Subject(s) - x ray photoelectron spectroscopy , quantum dot , detection limit , materials science , electrochemistry , nanotechnology , metal ions in aqueous solution , metal , gallium , analytical chemistry (journal) , biocompatibility , chemistry , chemical engineering , electrode , organic chemistry , chromatography , engineering , metallurgy
Owing to their high surface‐to‐volume ratio, electrocatalytic activity, biocompatibility and novel electron transport properties, quantum dots (QDs) are highly attractive materials for the ultrasensitive detection of biological macromolecules via bioelectronic devices. In this study, a QD‐based genosensor was developed, in which Ga 2 Te 3 ‐based QDs were synthesized using an aqueous solution approach by mixing 3‐mercaptosuccinic acid (3MSA)‐capped gallium metal precursor with reduced tellurium metal. The results enabled us to reach an original understanding related to the active material involved in the probe DNA sensing mechanism. The morphological and structural characterization of the QDs was performed prior to their utilization in a DNA sensor construction. High‐resolution TEM (HR‐TEM) and atomic force microscopy (AFM) images confirmed the spherical and crystalline nature of the QDs, whereas X‐ray photoelectron spectroscopy ( XPS ) and X ‐ray diffraction (XRD) analyses were able to confirm the oxidation states and formation of the prepared QDs. UV/Vis was capable of finding the optical band gap energy and the photostability of the QDs. The resultant Ga 2 Te 3 QDs together with metal ions confirmed their use for DNA signal detection through their DNA binding mechanism in the genosensor construction. Genosensing in Cs + and Li + ions exhibited high sensitivity (2.74–3.69 μA ng −1 mL) and very low detection limits (0.4 pg mL −1 ) with a linear dynamic range of 0.1–1 ng mL −1 .