Conjugation of cysteamine functionalized nanodiamond to gold nanoparticles for pH enhanced colorimetric detection of Cr3+ ions demonstrated by real water sample analysis

Muthaiah Shellaiah, Kien Wen Sun*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

A cysteamine functionalized nanodiamond (NDC) was conjugated to gold nanoparticles (AuNPs) to deliver NDC@AuNPs and utilized in enhanced colorimetric detection of Cr3+ at pH 6 environment. The conjugation was validated using FTIR, TEM, PXRD, DLS, and zeta potential investigations. At pH 6, superior sensory response of NDC@AuNPs to Cr3+ than that of other ions was validated by UV–vis spectroscopy and colorimetric photographs. Results from UV–vis titrations displayed a linear regression from 0.01 to 0.4 µM with a LOD of 0.236 ± 0.005 nM. The particle aggregation, size variations, potential changes, and binding modes are investigated using TEM, DLS, and FTIR techniques to explore the underlying mechanisms. By adding the EDTA, sensory response is reversible up to 4 cycles. Finally, spiked real water experiments show improved sensing of Cr3+ at pH 6 via the observed recovery between 96 and 110 %, which is in good agreement with the ICP-mass data.

Original languageEnglish
Article number121962
JournalSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
Volume286
DOIs
StatePublished - 5 Feb 2023

Keywords

  • Conjugated AuNPs
  • Cr ion
  • Cysteamine capped nanodiamond
  • Nanomolar detection
  • pH enhanced quantitation
  • Real water studies
  • Reversibility

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