Studies on carbon-quantum-dot-embedded iron oxide nanoparticles and their electrochemical response
A report on the synthesis of carbon-quantum-dot-embedded iron oxide nanoparticles (CQD@Fe3O4NPs) and their improved electrochemical studies is presented. Fe3O4NPs and CQD@Fe3O4NPs were synthesized by the wet-chemical co-precipitation method. X-ray diffraction measurements exhibited pure cubic phase...
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Published in | Nanotechnology Vol. 31; no. 35; p. 355502 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
IOP Publishing
28.08.2020
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Subjects | |
Online Access | Get full text |
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Summary: | A report on the synthesis of carbon-quantum-dot-embedded iron oxide nanoparticles (CQD@Fe3O4NPs) and their improved electrochemical studies is presented. Fe3O4NPs and CQD@Fe3O4NPs were synthesized by the wet-chemical co-precipitation method. X-ray diffraction measurements exhibited pure cubic phase with Fd3m space group in Fe3O4NPs and CQD@Fe3O4NPs. Fourier-transform infrared spectroscopy measurements confirmed the functionalization of Fe3O4NPs with CQDs. Dynamic light scattering measurements revealed a hydrodynamic radius of 520 nm and 319 nm for Fe3O4NPs and CQD@Fe3O4NPs, respectively. Moreover, zeta potential measurements showed positively charged Fe3O4NPs and negatively charged CQD@Fe3O4NPs. High-resolution transmission electron microscopy measurements showed nearly spherical structure with an average size of around 7 nm for Fe3O4 in both samples, whereas CQDs were nearly 2 nm in size in CQD@Fe3O4NPs. A biocompatibility study showed that CQD@Fe3O4NPs were more biocompatible than the bare Fe3O4NPs. CQD@Fe3O4NPs were then dispersed in chitosan (CHIT) solution, and drop-casted onto an indium tin oxide (ITO) glass substrate for further study. Atomic force microscopy results showed improved surface roughness of the CQD@Fe3O4−CHIT/ITO electrode, providing a better biosensing platform. The electrochemical response studies of CQD@Fe3O4−CHIT/ITO also showed enhanced electrochemical signal compared to Fe3O4−CHIT/ITO electrodes. Thus, a CQD@Fe3O4−CHIT/ITO electrode was used for the detection of vitamin D2 (10-100 ng ml−1) using a differential pulse voltammetry technique. The sensitivity and limit of detection were obtained as 0.069 µA ng−1 ml cm−2 and 2.46 ng ml−1, respectively. |
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Bibliography: | NANO-125679.R1 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0957-4484 1361-6528 |
DOI: | 10.1088/1361-6528/ab925e |