Cytosine-Rich Oligonucleotide and Electrochemically Reduced Graphene Oxide Nanocomposite for Ultrasensitive Electrochemical Ag<SUP>+</SUP> Sensingopen access
- Authors
- Abbas, Nasir; Jang, Seung Joo; Kim, Tae Hyun
- Issue Date
- May-2024
- Publisher
- MDPI
- Keywords
- reduced graphene oxide; DNA hairpin; silver ion; electrochemical aptasensor
- Citation
- NANOMATERIALS, v.14, no.9
- Journal Title
- NANOMATERIALS
- Volume
- 14
- Number
- 9
- URI
- https://scholarworks.bwise.kr/sch/handle/2021.sw.sch/26198
- DOI
- 10.3390/nano14090775
- ISSN
- 2079-4991
2079-4991
- Abstract
- Silver ions (Ag+) are crucial in various fields, but pose environmental and health risks at high concentrations. This study presents a straightforward approach for the ultra-trace detection of Ag+, utilizing a composite of a cytosine-rich oligonucleotide (CRO) and an electrochemically reduced graphene oxide (ERGO). Initially, ERGO was synthesized on a glassy carbon electrode (GCE) through the reduction of graphene oxide (GO) via cyclic voltammetry. A methylene blue-tagged CRO (MB-CRO) was then anchored to the ERGO surface through pi-pi interactions, resulting in the formation of an MB-CRO-modified ERGO electrode (MB-CRO/ERGO-GCE). The interaction with Ag+ ions induced the formation of silver-mediated C-Ag+-C coordination, prompting the MB-CRO to adopt a hairpin structure. This conformational change led to the desorption of the MB-CRO from the ERGO-GCE, causing a variation in the redox current of the methylene blue associated with the MB-CRO. Electrochemical assays revealed that the sensor exhibits extraordinary sensitivity to Ag+ ions, with a linear detection range from 1 femtomolar (fM) to 100 nanomolars (nM) and a detection limit of 0.83 fM. Moreover, the sensor demonstrated high selectivity for Ag+ ions and several other benefits, including stability, reproducibility, and straightforward fabrication and operational procedures. Additionally, real sample analyses were performed using the modified electrode to detect Ag+ in tap and pond water samples, yielding satisfactory recovery rates.
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Collections - College of Natural Sciences > Department of Chemistry > 1. Journal Articles
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