Smart Mn7+ Sensing via Quenching on Dual Fluorescence of Eu3+ Complex-Modified TiO2 Nanoparticles

Wenbin Yang; Siqi Niu; Yao Wang; Linjun Huang; Shichao Wang; Ketul C Popat; Matt J Kipper; Laurence A Belfiore; Jianguo Tang

doi:10.3390/nano11123283

Smart Mn⁷⁺ Sensing via Quenching on Dual Fluorescence of Eu³⁺ Complex-Modified TiO₂ Nanoparticles

Nanomaterials (Basel). 2021 Dec 3;11(12):3283. doi: 10.3390/nano11123283.

Authors

Wenbin Yang¹, Siqi Niu¹, Yao Wang¹, Linjun Huang¹, Shichao Wang¹, Ketul C Popat^{2

3}, Matt J Kipper^{3

4}, Laurence A Belfiore⁴, Jianguo Tang¹

Affiliations

¹ National Center of International Joint Research for Hybrid Materials Technology, National Base of International Sci. & Tech. Cooperation on Hybrid Materials, Qingdao University, 308 Ningxia Road, Qingdao 266071, China.
² Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA.
³ School of Biomedical Engineering/School of Advanced Materials Discovery, Colorado State University, Fort Collins, CO 80523, USA.
⁴ Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO 80523, USA.

Abstract

In this work, titania (TiO₂) nanoparticles modified by Eu(TTA)₃Phen complexes (ETP) were prepared by a simple solvothermal method developing a fluorescence Mn⁷⁺ pollutant sensing system. The characterization results indicate that the ETP cause structural deformation and redshifts of the UV-visible light absorptions of host TiO₂ nanoparticles. The ETP also reduce the crystallinity and crystallite size of TiO₂ nanoparticles. Compared with TiO₂ nanoparticles modified with Eu³⁺ (TiO₂-Eu³⁺), TiO₂ nanoparticles modified with ETP (TiO₂-ETP) exhibit significantly stronger photoluminescence under the excitation of 394 nm. Under UV excitation, TiO₂-ETP nanoparticles showed blue and red emission corresponding to TiO₂ and Eu³⁺. In addition, as the concentration of ETP in TiO₂ nanoparticles increases, the PL intensity at 612 nm also increases. When ETP-modified TiO₂ nanoparticles are added to an aqueous solution containing Mn⁷⁺, the fluorescence intensity of both TiO₂ and ETP decreases. The evolution of the fluorescence intensity ratio (I₁/I₂) of TiO₂ and ETP is linearly related to the concentration of Mn⁷⁺. The sensitivity of fluorescence intensity to Mn⁷⁺ concentration enables the design of dual fluorescence ratio solid particle sensors. The method proposed here is simple, accurate, efficient, and not affected by the environmental conditions.

Keywords: Eu(TTA)3Phen; Eu3+; Mn7+; TiO2 nanoparticle; fluorescence sensor.

Grants and funding

51473082, 51878361/jianguo tang