Single-center Ln(III) ratiometric luminescent temperature probes based on singlet -> singlet and singlet -> triplet sensitizations

Author(s)

Bispo-Jr, Airton Germano ; Mazali, Italo Odone ; Sigoli, Fernando Aparecido

• Document type: Journal article
• Source: JOURNAL OF MATERIALS CHEMISTRY C; v. 10, n. 38, p. 8-pg., 2022-08-15.

Abstract

Luminescence thermometry based on Ln(III) systems has become a hotspot in nanotechnology, biotechnology, and integrated optics, whereas the self-calibrated two-band intensity ratiometric method excels in this. Herein, propyldiphenylphosphine oxide (pdppo)-functionalized polydimethylsiloxane (PDMS) was reacted with [Ln(X-bza)(3)(H2O)(2)] complexes (Ln = Eu, Tb, or Yb, X-bza = 3,5-dichlorobenzoate or 3,5-dibromo benzoate) leading to chemically bound [Ln(X-bza)(3)(pdppo)(2)]-PDMS membranes. The systems were used as luminescent temperature probes by exploiting a new strategy based on two different thermally dependent excitation channels arising from spin-allowed singlet -> singlet or spin forbidden singlet -> triplet transitions. To define the thermometric parameter, the intensity ratio of the Ln(III) emission spectra measured upon singlet -> singlet or singlet -> triplet excitation was considered, which enables achieving ratiometric single-centered Eu-III or Tb-III or Yb-III-based luminescent temperature probes within 50-320 K. The maximum thermal sensitivity lies within 0.5-1.6% K-1 whereas the largest value was accomplished for [Yb(3,5-bbza)(3)(pdppo)(2)]-PDMS (1.6% K-1 at 120 K), which is among the best value reported for NIR-emitting single-center Ln(III) luminescent temperature probes. (AU)

• FAPESP's process: 12/11382-9 - Optical modulation of semiconductor nanostructures using surface acoustic waves
• Grantee: Odilon Divino Damasceno Couto Júnior
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 13/22127-2 - Development of novel materials strategic for integrated analytical devices
• Grantee: Lauro Tatsuo Kubota
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 21/06326-1 - Luminescence of lanthanide ions: an optical tool against counterfeiting
• Grantee: Fernando Aparecido Sigoli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/02614-0 - White-emitting silicates doped with lanthanide and transition metal ions for application in warm white-light-emitting diodes
• Grantee: Marian Rosaly Davolos
• Support Opportunities: Regular Research Grants