scholarly journals Sensitive Detection of Sulfide Ion Based on Fluorescent Ionic Liquid–Graphene Quantum Dots Nanocomposite

2021 ◽  
Vol 9 ◽  
Author(s):  
Guanhua Qiu ◽  
Yaoqi Han ◽  
Xiaoqi Zhu ◽  
Jiawei Gong ◽  
Tao Luo ◽  
...  

Sulfide ions (S2−) that are widely distributed in biological and industrial fields are extremely toxic and pose great harms to both ecological environment and human health. However, fluorescent sensors toward S2− ions commonly use S2−-recovered fluorescence of fluorophore that is first quenched mainly by metal ions. Fluorescent probe which enables direct, selective, and sensitive detection of S2− ion is highly desirable. Herein, we demonstrate one-step preparation of fluorescent ionic liquid–graphene quantum dots (IL-GQDs) nanocomposite, which can act as a fluorescent probe for direct and sensitive detection of S2− ion. The IL-GQDs nanocomposite is easily synthesized via facile molecular fusion of carbon precursor and in situ surface modification of GQDs by IL under hydrothermal condition. The as-prepared IL-GQDs nanocomposite has uniform and ultrasmall size, high crystallinity, and bright green fluorescence (absolute photoluminescence quantum yield of 18.2%). S2− ions can strongly and selectively quench the fluorescence of IL-GQDs because of the anion exchange ability of IL. With IL-GQDs nanocomposite being fluorescent probe, direct and sensitive detection of S2− is realized with a linear detection range of 100nM–10μM and 10μM–0.2mM (limit of detection or LOD of 23nM). Detection of S2− ions in environmental river water is also achieved.

2021 ◽  
Vol 9 ◽  
Author(s):  
Zheng Yanyan ◽  
Jing Lin ◽  
Liuhong Xie ◽  
Hongliang Tang ◽  
Kailong Wang ◽  
...  

Simple and efficient synthesis of graphene quantum dots (GQDs) with anodic electrochemiluminescence (ECL) remains a great challenge. Herein, we present an anodic ECL-sensing platform based on nitrogen-doped GQDs (N-GQDs), which enables sensitive detection of hydrogen peroxide (H2O2) and glucose. N-GQDs are easily prepared using one-step molecular fusion between carbon precursor and a dopant in an alkaline hydrothermal process. The synthesis is simple, green, and has high production yield. The as-prepared N-GQDs exhibit a single graphene-layered structure, uniform size, and good crystalline. In the presence of H2O2, N-GQDs possess high anodic ECL activity owing to the functional hydrazide groups. With N-GQDs being ECL probes, sensitive detection of H2O2 in the range of 0.3–100.0 μM with a limit of detection or LOD of 63 nM is achieved. As the oxidation of glucose catalyzed by glucose oxidase (GOx) produces H2O2, sensitive detection of glucose is also realized in the range of 0.7–90.0 μM (LOD of 96 nM).


2014 ◽  
Vol 86 (20) ◽  
pp. 10201-10207 ◽  
Author(s):  
Shuhua Li ◽  
Yunchao Li ◽  
Jun Cao ◽  
Jia Zhu ◽  
Louzhen Fan ◽  
...  

2016 ◽  
Vol 664 ◽  
pp. 127-132 ◽  
Author(s):  
Yan Li ◽  
Xinqian Liu ◽  
Qiyao Li ◽  
Juan Ge ◽  
Hui Liu ◽  
...  

Author(s):  
Peyman Mohammadzadeh Jahani

The electrochemical sensor was fabricated for the simultaneous determination of levodopa and cabergoline using carbon paste electrode (CPE) modified with graphene quantum dots (GQD), 2-chlorobenzoyl ferrocene (2CBF) and ionic liquid (IL). Then, the electrochemical behavior of levodopa alone and simultaneously with cabergoline at the surface of GQDs/2CBF/IL/CPE was investigated in phosphate buffer solution (PBS). Under optimal PBS, pH=7 condition, oxidation peak current has been found proportional to levodopa concentration in the range between 0.07 μM and 500.0 μM, with the limit of detection (LOD) of 0.02 μM (S/N=3). Outputs showed that at GQDs/2CBF/IL/CPE surface, the levodopa and cabergoline oxidation peaks are separated by the potential difference of 200 mV. In addition, it was found that this modified electrode possesses acceptable sensitivity, selectivity, stability and repeatability. All these properties were sufficient to allow simultaneous detection of levodopa and cabergoline in real samples at the surface of GQDs/2CBF/IL/CPE. This was supported by the successful application of this electro­chemical sensor electrode for the determination of levodopa and cabergoline in urine, serum, and cabergoline tablets.


RSC Advances ◽  
2016 ◽  
Vol 6 (74) ◽  
pp. 69977-69983 ◽  
Author(s):  
Shiyue Bian ◽  
Chao Shen ◽  
Hong Hua ◽  
Lin Zhou ◽  
Hailin Zhu ◽  
...  

A facile strategy was developed for the one-step synthesis of S-GQDs with a monolayer-graphene crystal structure. The change of surface chemistry by S-doping resulted in selective and sensitive detection of Pb2+.


2020 ◽  
Vol 92 (11) ◽  
pp. 7988-7988
Author(s):  
Shuhua Li ◽  
Yunchao Li ◽  
Jun Cao ◽  
Jia Zhu ◽  
Louzhen Fan ◽  
...  

2015 ◽  
Vol 182 (13-14) ◽  
pp. 2139-2146 ◽  
Author(s):  
Ningxiang Yu ◽  
Hailong Peng ◽  
Hua Xiong ◽  
Xiaqing Wu ◽  
Xiaoyan Wang ◽  
...  

2015 ◽  
Vol 891 ◽  
pp. 261-268 ◽  
Author(s):  
Liping Lin ◽  
Xinhong Song ◽  
Yiying Chen ◽  
Mingcong Rong ◽  
Yiru Wang ◽  
...  

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