Red-Emitting Hybrid Based on Eu3+-dbm Complex Anchored on Silica Nanoparticles Surface by Carboxylic Acid for Biomarker Application

Author(s)

Santos, Joao A. O. ^{[1, 2, 3]} ; Mutti, Alessandra M. G. ^{[2, 3]} ; Bispo-Jr, Airton G. ; Pires, Ana M. ^{[2, 3, 4]} ; Lima, Sergio A. M. ^[3]

Affiliation

^[1] Sao Paulo State Univ, Inst Chem, UNESP, BR-14800900 Araraquara, SP - Brazil

^[2] Sao Paulo State Univ, UNESP, Inst Biosci Humanities & Exact Sci, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

^[3] Sao Paulo State Univ, Sch Technol & Sci, UNESP, BR-19060900 Presidente Prudente, SP - Brazil

^[4] Bispo-Jr, Jr., Airton G., Sao Paulo State Univ, Inst Chem, UNESP, BR-14800900 Araraquara, SP - Brazil

• Document type: Journal article
• Source: MATERIALS; v. 13, n. 23 DEC 2020.
• Web of Science Citations: 0

Abstract

Luminescent organic-inorganic hybrids containing lanthanides (Ln(3+)) have been prominent for applications such as luminescent bio-probes in biological assays. In this sense, a luminescent hybrid based on dense silica (SiO2) nanospheres decorated with Eu3+ beta-diketonate complexes using dibenzoylmethane (Hdbm) as a luminescent antenna was developed by using a hierarchical organization in four steps: (i) anchoring of 3-aminopropyltriethoxysilane (APTES) organosilane on the SiO2 surface, (ii) formation of a carboxylic acid ligand, (iii) coordination of Eu3+ to the carboxylate groups and (iv) coordination of dbm(-) to Eu3+. The hybrid structure was elucidated through the correlation of thermogravimetry, silicon nuclear magnetic resonance and photoluminescence. Results indicate that the carboxylic acid-Eu3+-dbm hybrid was formed on the surface of the particles with no detectable changes on their size or shape after all the four steps (average size of 32 +/- 7 nm). A surface charge of -27.8 mV was achieved for the hybrid, assuring a stable suspension in aqueous media. The Eu3+ complex provides intense red luminescence, characteristic of Eu3+ D-5(0)-> F-7(J) electronic transitions, with an intrinsic emission quantum yield of 38%, even in an aqueous suspension. Therefore, the correlation of luminescence, structure, particle morphology and fluorescence microscopy images make the hybrid promising for application in bioimaging. (AU)

• FAPESP's process: 19/26103-7 - Silica particles decorated with luminescent complexes for application in sensors and cellular imaging
• Grantee: Sergio Antonio Marques de Lima
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/04907-3 - Schiff base funcionalized silica nanoparticles
• Grantee: João Antonio Oliveira Santos
• Support Opportunities: Scholarships in Brazil - Scientific Initiation