A New Cellulose-Based Fluorescent Probe for Specific and Sensitive Detection of Cu2+ and Its Applications in the Analysis of Environmental Water

Abstract

In this work, a novel fluorescent probe CMC−GE−AQ with an effective sensitive detection ability for Cu2+ was synthesized and constructed by using carboxymethyl cellulose (CMC) as the skeleton and 8-aminoquinoline (AQ) as the fluorophore. This probe exhibited a highly specific “turn-off” fluorescence response to Cu2+, and the fluorescence color changed from bright orange to colorless after adding Cu2+. The probe could selectively detect Cu2+ in a complex environment and its detection limit (LOD), the binding constant (Ka) and the numbers of binding sites (n) were calculated to be 6.4 × 10−8 mol L−1, 1.7 × 106 mol−1 L and 1.2, respectively. The sensing detection mechanism was confirmed by X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. In addition, the probe CMC−GE−AQ was successfully applied to detect Cu2+ in real water samples, and CMC−GE−AQ-based fluorescent microspheres can serve as a convenient tool for the detection of Cu2+.

Folic Acid Adjustive Polydopamine Organic Nanoparticles Based Fluorescent Probe for the Selective Detection of Mercury Ions

“…For all we know that the N/C value of FA is 0.43, and the N/C value ranges of PDA is often from 0.08 to 0.17, interestingly, the N/C value of FA-PDA FONs here is 0.226, therefore, FA-PDA FONs may be hybrid materials and composed of folic acid, polydopamine, even Tris moieties [37]. As represented in Figure 3b, the C1s region can be integrated into four major component bands: C-C/C=C (284.82 eV), C-N/C-O (286.23 eV), C-C=O (287.70 eV), and C=N (288.63 eV) [5,38], correspondingly. In addition, the N1s region has three bands: C=N-R (398.6 eV), R 1 -NH-R 2 (399.06 eV), and R-NH 2 (401.87 eV), respectively [32], and the O1s region is fitted with two prominent bands: O-C (532.9 eV) and O=C (531.85 eV) [12,32].…”