Open AccessUltratrace Detection of Nickel(II) Ions in Water Samples Using Dimethylglyoxime-Doped GQDs as the Induced Metal Complex Nanoparticles by a Resonance Light Scattering Sensor
Author(s) -
Nipaporn Pimsin,
Niradchada Kongsanan,
Chayanee Keawprom,
Phitchan Sricharoen,
Prawit Nuengmatcha,
WonChun Oh,
Yonrapach Areerob,
Saksit Chanthai,
Nunticha Limchoowong
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c00190
Subject(s) - analytical chemistry (journal) , detection limit , chemistry , spectroscopy , dimethylglyoxime , graphene , quantum yield , materials science , nickel , nuclear chemistry , fluorescence , chromatography , nanotechnology , physics , organic chemistry , quantum mechanics
This study aimed to synthesize dimethylglyoxime (DMG) (N-source)-doped graphene quantum dots (N-GQDs) via simultaneous pyrolysis of citric acid and 1.0% (w/v) DMG. The maximum excitation wavelength (λ max , ex = 380 nm) of the N-GQD solution (49% quantum yield (QY)) was a red shift with respect to that of bare GQDs (λ max , ex = 365 nm) (46% QY); at the same maximum emission wavelength (λ max , em = 460 nm), their resonance light scattering (RLS) intensity peak was observed at λ max , ex/em = 530/533 nm. FTIR, X-ray photoelectron spectroscopy, XRD, energy-dispersive X-ray spectroscopy, and transmission electron microscopy analyses were performed to examine the synthesized materials. The selective and sensitive detection of Ni 2+ using the RLS intensity was performed at 533 nm under the optimum conditions consisting of both 25 mg L -1 N-GQDs and 2.5 mg L -1 DMG in the ammonium buffer solution of pH 9.0. The linearity of Ni 2+ was 50.0-200.0 μg L -1 with a regression line, y = 5.031 x - 190.4 ( r 2 = 0.9948). The limit of detection (LOD) and the limit of quantitation (LOQ) were determined to be 20.0 and 60.0 μg L -1 , respectively. The method precision expressed as % RSDs was 4.90 for intraday ( n = 3 × 3) and 7.65 for interday ( n = 5 × 3). This developed method afforded good recoveries of Ni 2+ in a range of 85-108% when spiked with real water samples. Overall, this innovative method illustrated the identification and detection of Ni 2+ as a DMG complex with N-GQDs, and the detection was highly sensitive and selective.