Fluorescent detection of Cu(II) by chitosan-based AIE bioconjugate

• Published in: Chinese journal of polymer science Vol. 35; no. 3; pp. 365 - 371
• Main Authors: Liu, Ya-lan, Wang, Zheng-ke, Qin, Wei, Hu, Qiao-ling, Tang, Ben Zhong
• Format: Journal Article
• Language: English
• Published: Beijing Chinese Chemical Society and Institute of Chemistry, CAS 01.03.2017; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chitosan; Complexation; Condensed Matter Physics; Copper; Electron transfer; Environmental monitoring; Fluorescence; Heavy metals; Industrial Chemistry/Chemical Engineering; Lead (metal); Mercury (metal); Metal ions; Polymer Sciences; Quenching (cooling); Fluorescent detection; Aggregation-induced emission; Chitosan; Cu(II)
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-017-1876-y

Detection of Cu(II) is very important in disease diagnose, biological system detection and environmental monitoring. Previously, we found that the product TPE-CS prepared by attaching the chromophores of tetraphenylethylene (TPE) to the chitosan (CS) chains showed excellent fluorescent properties. In this study, we tried to use TPE-CS for detecting Cu(II) because of the stable complexation of CS with heavy metals and the luminosity mechanism of the Restriction of Intramolecular Rotations (RIR) for aggregation-induced emission (AIE)-active materials. The fluorescence intensity changed when TPE-CS was contacted with different metal ions, to be specific, no change for Na + , slightly increase for Hg 2+ , Pb 2+ , Zn 2+ , Cd 2+ , Fe 2+ , Fe 3+ due to the RIR caused by the complexation between CS and metal ions. However, for Cu 2+ , an obvious fluorescence decrease was observed because of the Photoinduced-Electron-Transfer (PET). Moreover, we found that the quenched FL intensity of TPE-CS was proportional to the concentration of Cu(II) in the range of 5 μmol/L to 100 μmol/L, which provided a new way to quantitatively detect Cu(II). Besides, TPE-CS has excellent water-solubility as well as absorbability (the percentage of removal, R = 84%), which is an excellent detection probe and remover for Cu(II).