Self-Assembly Fluorescent Cationic Cellulose Nanocomplex via Electrostatic Interaction for the Detection of Fe3+ Ions.

Haoying Wang,Jinping Zhou,Xiu Ye

doi:10.3390/nano9020279

Abstract

In this work, an aggregation-induced emission (AIE) sensor for the detection of Fe3+ ions was fabricated through the electrostatic interaction between 1,1,2-triphenyl-2-[4-(3-sulfonatopropoxyl)-phenyl]-ethene sodium salt (SPOTPE) and quaternized cellulose (QC). The structure and properties of the SPOTPE/QC nanocomplex were studied by using 1H NMR, spectrofluorophotometer, transmission electron microscopy (TEM), and dynamic laser light scattering (DLS). An aqueous solution of SPOTPE and QC resulted in a remarkably enhanced cyan fluorescence in comparison to that of the SPOTPE solution. Strong through-space electrostatic interaction between SPOTPE and QC is the main cause for the fluorescence emerging. The fluorescence of the SPOTPE/QC solutions show good stability over a wide pH range of 5.0–10.0. When introducing Fe3+ ions into the SPOTPE/QC solution, the fluorescence quenched within 5 s. SPOTPE/QC solutions exhibited high selectivity and sensitivity for the detection of Fe3+ ions with ignored interferences from other ions, and the detection limit was determined to be 2.92 × 10−6 M. The quenching mechanism was confirmed to be the consequence of the binding interactions between Fe3+ ions and SPOTPE/QC complex.

Highlights

Fe3+ is one of the most abundant and common metal ions and plays an important role in many fields, such as in the biological system, environment, and industrial areas [1]
SPOTPE and quaternized cellulose (QC) were dissolved in ultrapure water to obtain the stock solutions with concentrations of 2.0 mg/mL, which were stored at room temperature before use
A SPOTPE/QC fluorescent complex was successfully constructed for the detection of Fe3+ ions in aqueous solutions

Summary

Introduction

Fe3+ is one of the most abundant and common metal ions and plays an important role in many fields, such as in the biological system, environment, and industrial areas [1]. Many types of fluorescent probe have been designed based on two common phenomena [9,10], which are aggregation-caused quenching (ACQ) and aggregation-induced emission (AIE) [11]. TPE is a typical AIE molecule used mostly for detection, it cannot dissolve in aqueous solutions, which limits its application. Li et al constructed a fluorescent probe from charge-generation polymers and a TPE derivative, and the probe was well-dissolved in water and showed sensitivity to the presence of H2O2 or thiols [28]. Though the chemical reaction between water-soluble polymers and TPE molecules make them possible for applicating in water, the approaches are inefficient and difficult to operate [29,30,31]. The SPOTPE/QC solutions demonstrated a selective and sensitive detection to Fe3+ in the absence/presence of interfering metal ions, indicating potential applications in the field of chemosensing

Materials

Synthesis of SPOTPE

Characterizations

Conclusions