Fluorescent determination of fluazinam with polyethyleneimine-capped copper nanoclusters

doi:10.1016/j.cplett.2020.137748

Chemical Physics Letters

Volume 754, September 2020, 137748

https://doi.org/10.1016/j.cplett.2020.137748 Get rights and content

Highlights

•
The PEI-Cu NCs represented the polyethyleneimine protected copper nanoclusters.
•
The fluorescence of sample could be selectively quenched by addition of fluazinam.
•
The quenching mechanism might be dynamic quenching and inner filter effect (IFE).
•
The PEI-Cu NCs could be used to detect fluazinam in environmental water samples.

Abstract

The polyethyleneimine-capped copper nanoclusters (PEI-Cu NCs) were prepared by using polyethyleneimine as protective agent and hydrazine hydrate as reducing agent. The PEI-Cu NCs possessed strong fluorescence intensity, excellent water solubility, good stability and high dispersion. The sample’s fluorescence could be selectively quenched by the addition of fluazinam. There was a good linear relationship between the relative fluorescence intensity of PEI-Cu NCs and concentrations of fluazinam in the range of 0.5–70 μM. The quenching mechanism might be dynamic quenching and inner filter effect (IFE). Significantly, the PEI-Cu NCs could be used to detect fluazinam as fluorescent probe in environmental water samples.

Graphical abstract

A PEI-functionalized Cu NCs was employed to explore fluorescence determination of fluazinam in aqueous solution with high sensitivity and selectivity.

Introduction

Fluazinam, a broad-spectrum high-efficiency fungicide, has been widely used in agricultural production [1]. However, excessive application of fluazinam has already affected human’s organic histology and ecological environment. Therefore, it is vital to determine fluazinam in our living environment. Many measurement methods have been developed to analyse fluazinam, including gas chromatography [2], gas chromatography tandem mass spectrometry [3] and high performance liquid chromatography [4]. Although these methods display the advantages of high sensitivity and dependability, they also have some defects of time-consuming, high cost and professional operator. Therefore, the development of green, innovative, convenient, low cost, high selective and sensitive detection methods for fluazinam determination is very crucial.

Metal nanoclusters (MNCs), a new type of fluorescent material, have attracted a lot of attentions owing to their characteristics of strong fluorescence, high quantum-yield, good water solubility and biocompatibility, excellent photostability and stability [5], [6], [7], [8], [9]. So far, MNCs has been applied for bioanalysis, bioimaging, environmental monitoring, industrial catalysis and electronic equipment [10], [11], [12]. Many synthesis means of etching method, electrochemical method, photoreduction method, sonochemical synthesis, microwave assisted method and template assisted synthesis have been developed to prepare MNCs, especially for Cu, Au and Ag nanoclusters [13], [14], [15], [16], [17], [18], [19]. Meanwhile, some protective agents and stabilizers are used to synthesize Cu NCs, including DNAs, protein, polymer and thiols [20], [8], [21], [22]. Cu NCs have been used as high sensitive and selective fluorescent sensors to detect Hg²⁺ [23], Cd²⁺ [24], Fe³⁺ [18], Cu²⁺ [25], Al³⁺ [26], ClO⁻ [27], NO₂⁻ [28], H₂O₂ [29], glucose [30], trinitrophenol [31], trinitrotoluene [32] and so on. However, there are few reports of Cu NCs for the detection of fluazinam.

In this work, we prepared the Cu NCs of good water solubility by using polyethyleneimine as a protective agent and hydrazine hydrate as a reducing agent at 95 °C for 12 h. The samples were analysed through UV–visible absorption spectroscopy (UV–vis), fluorescence spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectrometer (XPS). Furthermore, we investigated the effects of storage time, UV irradiation time and concentration of NaCl on the fluorescence intensity of PEI-Cu NCs. More importantly, we established a high sensitive and selective fluorescence detection method for the analysis of fluazinam in environmental water samples.

Section snippets

Apparatus

The fluorescence spectra were recorded on F-7000 fluorescence spectrophotometer (Hitachi, Tokyo Japan) under the voltage of 400 V, in which the E_x/E_m slits are 10.0/10.0 nm and the scanning speed is 1200 nm⋅min⁻¹. The UV–vis absorption spectra were obtained by using a Shimadzu 2450 UV–visible spectrophotometer (Shimadzu, Japan). The transmission electron microscopy (TEM) image was acquired by using FEI Tecnai G2 F20 (United States) at an acceleration voltage of 200 kV. X-ray photoelectron

Characterization of the PEI-Cu NCs

To investigate the structure, composition and optical performance of PEI-Cu NCs, the fluorescence spectroscopy, UV–vis absorption spectroscopy, TEM and XPS were employed. As displayed in Fig. 1A, the fluorescence of PEI-Cu NCs demonstrated maximum excitation and emission peaks at 352 and 472 nm, respectively. In addition, the PEI-Cu NCs solutions were light blue under visible light and green under UV light (inset in Fig. 1A). In Fig. 1B, the emission wavelength of PEI-Cu NCs gradually changed

Conclusions

In summary, we synthesized water-soluble fluorescence Cu NCs through a one-pot and simple method. The PEI-Cu NCs had strong fluorescence intensity, excellent water solubility, good stability and high dispersion. To our knowledge, the PEI-Cu NCs was firstly used to detect fluazinam. The detection linear range was 0.5–70 μM and the quenching mechanism might be dynamic quenching and inner filter effect (IFE). In addition, this fluorescence analysis method had been successfully utilized to

CRediT authorship contribution statement

Yuyu Guo: Conceptualization, Methodology, Software, Writing - original draft, Writing - review & editing. Shuxuan Shi: Formal analysis, Investigation. Chunyan Fan: Investigation. Dan Jin: Investigation.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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Research paperFluorescent determination of fluazinam with polyethyleneimine-capped copper nanoclusters

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Apparatus

Characterization of the PEI-Cu NCs

Conclusions

CRediT authorship contribution statement

Declaration of Competing Interest

Environ. Monit. Assess

NeuroToxicology

Biosens. Bioelectron.

J. Lumin.

Biosens. Bioelectron.

Trac-Trend Anal. Chem.

Anal. Chim. Acta

Talanta

Sensor Actuat. B-Chem.

Spectrochim. Acta A

Spectrochim. Acta Part A

Sensor Actuators B

High-performance liquid chromatography (HPLC) as a tool for monitoring the fate of fluazinam in soil

J. Environ. Sci. Health Part B

Determination of Fungicide Kresoxim-Methyl Residues in Cucumber and Soil by Capillary Gas Chromatography with Nitrogen-Phosphorus Detection

J. Environ. Sci. Health Part B

Role of size and shape selectivity in interaction between gold nanoclusters and imidazole: a theoretical study

J. Mol. Modeling

Tannic Acid Stabilised Copper Nanocluster Developed Through Microwave Mediated Synthesis as a Fluorescent Probe for the Turn on Detection of Dopamine

J. Clust. Sci.

Reversible fluorescence modulation of BSA stabilised copper nanoclusters for the selective detection of protamine and heparin

Analyst

Photoluminescent AuCu bimetallic nanoclusters as pH sensors and catalysts

Nanoscale

Research paper
Fluorescent determination of fluazinam with polyethyleneimine-capped copper nanoclusters