Mature green tea leaves derived CDs as both reducing agent and stabilizer for synthesis of CD-AgNPs composite for Hg(II) ions detection

A stable CD-AgNPs composite system has been synthesized with the carbon dots (CDs) that were synthesized from mature green tea leaves as a reducing and stabilizing agent. Accordingly, ambient temperature synthesis at the optimized process condition of 0.5 mL CDs solution, 10 mL of 5 mM silver nitrat...

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Main Authors: Swagata Patra, Animes K. Golder, Ramagopal V.S. Uppaluri
Format: Article
Language:English
Published: Elsevier 2025-01-01
Series:Next Nanotechnology
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Online Access:http://www.sciencedirect.com/science/article/pii/S2949829525000889
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author Swagata Patra
Animes K. Golder
Ramagopal V.S. Uppaluri
author_facet Swagata Patra
Animes K. Golder
Ramagopal V.S. Uppaluri
author_sort Swagata Patra
collection DOAJ
description A stable CD-AgNPs composite system has been synthesized with the carbon dots (CDs) that were synthesized from mature green tea leaves as a reducing and stabilizing agent. Accordingly, ambient temperature synthesis at the optimized process condition of 0.5 mL CDs solution, 10 mL of 5 mM silver nitrate (AgNO3) and 2 h reaction time were analysed to be the optimal process condition for the synthesis of highly sensitive and selective monodispersed CD-AgNPs and for Hg(II) sensing application. The synthesized CD-AgNPs were characterized with UV-Visible spectroscopy (426 nm), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Field Emission Transmission Electron Microscopy (FETEM). The contacting of Hg(II) solution and the composite nanosystem at the 4 pH ascertained a color alteration from the reddish brown hue to the colorless state. Also, the color transition corroborated with the blue shift of localized surface plasmon resonance (LSPR) band and reduced absorbance of the CD-AgNPs composite. Integrating the finer findings of the XRD, FETEM and XPS analyses, the pertinent mechanism has been hypothesized in terms of the silver-mercury amalgam formation through the redox reaction between the CD-AgNPs composite system and Hg(II) system. In the deployed Hg(II) concentration range of 0.1–10 mg/L, the absorbance of the system altered as a linear model with good fitness. Thereby, the lowest LOD value of 0.009 mg/L was achieved. In summary, a highly sensitive system for Hg(II) detection has been confirmed and the interference effect has been insignificant with respect to other metal ions.
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spelling doaj-art-4a0922b3550e4ef8a688c7dc433a2a282025-08-20T03:51:25ZengElsevierNext Nanotechnology2949-82952025-01-01810021910.1016/j.nxnano.2025.100219Mature green tea leaves derived CDs as both reducing agent and stabilizer for synthesis of CD-AgNPs composite for Hg(II) ions detectionSwagata Patra0Animes K. Golder1Ramagopal V.S. Uppaluri2Centre for the Environment, Indian Institute of Technology Guwahati, Assam, IndiaCentre for the Environment, Indian Institute of Technology Guwahati, Assam, India; Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam, IndiaCentre for the Environment, Indian Institute of Technology Guwahati, Assam, India; Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam, India; Corresponding author at: Centre for the Environment, Indian Institute of Technology Guwahati, Assam, India.A stable CD-AgNPs composite system has been synthesized with the carbon dots (CDs) that were synthesized from mature green tea leaves as a reducing and stabilizing agent. Accordingly, ambient temperature synthesis at the optimized process condition of 0.5 mL CDs solution, 10 mL of 5 mM silver nitrate (AgNO3) and 2 h reaction time were analysed to be the optimal process condition for the synthesis of highly sensitive and selective monodispersed CD-AgNPs and for Hg(II) sensing application. The synthesized CD-AgNPs were characterized with UV-Visible spectroscopy (426 nm), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Field Emission Transmission Electron Microscopy (FETEM). The contacting of Hg(II) solution and the composite nanosystem at the 4 pH ascertained a color alteration from the reddish brown hue to the colorless state. Also, the color transition corroborated with the blue shift of localized surface plasmon resonance (LSPR) band and reduced absorbance of the CD-AgNPs composite. Integrating the finer findings of the XRD, FETEM and XPS analyses, the pertinent mechanism has been hypothesized in terms of the silver-mercury amalgam formation through the redox reaction between the CD-AgNPs composite system and Hg(II) system. In the deployed Hg(II) concentration range of 0.1–10 mg/L, the absorbance of the system altered as a linear model with good fitness. Thereby, the lowest LOD value of 0.009 mg/L was achieved. In summary, a highly sensitive system for Hg(II) detection has been confirmed and the interference effect has been insignificant with respect to other metal ions.http://www.sciencedirect.com/science/article/pii/S2949829525000889Fully grown green tea leavesCD-AgNPsColorimetric sensingHg(II) detectionHighly selective
spellingShingle Swagata Patra
Animes K. Golder
Ramagopal V.S. Uppaluri
Mature green tea leaves derived CDs as both reducing agent and stabilizer for synthesis of CD-AgNPs composite for Hg(II) ions detection
Next Nanotechnology
Fully grown green tea leaves
CD-AgNPs
Colorimetric sensing
Hg(II) detection
Highly selective
title Mature green tea leaves derived CDs as both reducing agent and stabilizer for synthesis of CD-AgNPs composite for Hg(II) ions detection
title_full Mature green tea leaves derived CDs as both reducing agent and stabilizer for synthesis of CD-AgNPs composite for Hg(II) ions detection
title_fullStr Mature green tea leaves derived CDs as both reducing agent and stabilizer for synthesis of CD-AgNPs composite for Hg(II) ions detection
title_full_unstemmed Mature green tea leaves derived CDs as both reducing agent and stabilizer for synthesis of CD-AgNPs composite for Hg(II) ions detection
title_short Mature green tea leaves derived CDs as both reducing agent and stabilizer for synthesis of CD-AgNPs composite for Hg(II) ions detection
title_sort mature green tea leaves derived cds as both reducing agent and stabilizer for synthesis of cd agnps composite for hg ii ions detection
topic Fully grown green tea leaves
CD-AgNPs
Colorimetric sensing
Hg(II) detection
Highly selective
url http://www.sciencedirect.com/science/article/pii/S2949829525000889
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