Carbon Quantum Dots' Synthesis with a Strong Chemical Claw for Five Transition Metal Sensing in the Irving-Williams Series.

Anastasia Yakusheva,Lev Luchnikov,Anastasia Sayapina,Dmitry Arkhipov,Denis Kuznetsov,Gopalu Karunakaran

doi:10.3390/nano12050806

Abstract

Carbon quantum dots (CQDs) are an excellent eco-friendly fluorescence material, ideal for various ecological testing systems. Herein, we establish uniform microwave synthesis of the group of carbon quantum dots with specific functionalization of ethylenediamine, diethylenetriamine, and three types of Trilon (A, B and C) with chelate claws -C-NH3. CQDs’ properties were studied and applied in order to sense metal cations in an aquatic environment. The results provide the determination of the fluorescence quench in dots by pollutant salts, which dissociate into double-charged ions. In particular, the chemical interactions with CQDs’ surface in the Irving–Williams series (IWs) via functionalization of the negatively charged surface were ascribed. CQD-En and CQD-Dien demonstrated linear fluorescence quenching in high metal cation concentrations. Further, the formation of claws from Trilon A, Trilon B, and C effectively caught the copper and nickel cations from the solution due to the complexation on CQDs’ surface. Moreover, CQD-Trilon C presented chelating properties of the surface and detected five cations (Cu2+, Ni2+, Ca2+, Mg2+, Zn2+) from 0.5 mg/mL to 1 × 10−7 mg/mL in the Irving–William’s series. Dependence was mathematically attributed as an equation (ML regression model) based on the constant of complex formation. The reliability of the data was 0.993 for the training database.

Highlights

For carbon quantum dots (CQDs), the trend in synthesis was from natural carbon sources, which expanded the market for the dots due to their economic, reproducible, and environmentally friendly peculiarities [6]
All CQD groups show the consequent relations in the Irving–Williams series (IWs) series from one8 of cation to another
Sewing chelating claws on the surface demonstrates a strong correlation with complexation laws, the reactivity dependence on the Irving–Williams series

Summary

Introduction

In recent times, applying natural assembled nanomaterials is the primary strategy in eco–build environments [1]. Carbon quantum dots (CQDs) are zero-dimensional carbon nanomaterials with an amorphous core and functional groups on the surface [3]. They have gained much attention among various emissive dots with quantum effects, such as MeO nanoparticles [4] or semiconduction cadmium, germanium, indium, or zinc-containing zero-dimensional materials [5]. For CQDs, the trend in synthesis was from natural carbon sources, which expanded the market for the dots due to their economic, reproducible, and environmentally friendly peculiarities [6]. This technology opens up new avenues for controlling the natural environment and has been successfully applied in the water assay [7]

Methods

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Discussion

Conclusion