| Full text | |
| Author(s): |
Marques, Nathalia da Silva
[1]
;
Nassar, Eduardo Jose
[1]
;
Verelst, Marc
[2]
;
Mauricot, Robert
[2]
;
Brunckova, Helena
[3]
;
Rocha, Lucas Alonso
[1]
Total Authors: 6
|
| Affiliation: | [1] Univ Franca, Ave Dr Armando de Sales Oliveira, 201 Parque Univ, BR-14404600 Franca, SP - Brazil
[2] Univ Toulouse, CEMES, CNRS, Toulouse - France
[3] Slovak Acad Sci, Inst Mat Res, Watsonova - Slovakia
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | ADVANCES IN MEDICAL SCIENCES; v. 65, n. 2, p. 324-331, SEP 2020. |
| Web of Science Citations: | 0 |
| Abstract | |
Purpose: This work investigates how Yb3+ concentration affects the luminescent properties of LaNbO4 nanoparticles for medical imaging applications. Due to the highly transparent optical window for organic tissues in the near infrared region (650-1000 nm), upconversion fluorescence allows near infrared wavelengths to penetrate deeply into tissues, which is useful in biomedical areas such as biodetection, activated phototherapy, and screening. Materials/method: Upconversion nanoparticles based on LaNbO4 doped with Tm3+ and Yb3+ were prepared by the one-step industrial process called Spray Pyrolysis. Samples with different Tm3+:Yb3+ molar ratios (1:4, 1:8 and 1:16) were obtained. Results: The X-ray powder diffractograms of all the samples displayed the typical peaks of a crystalline material (tetragonal phase). Emission bands emerged in the blue, red, and near infrared regions, and they corresponded to the Tm3+ (1)G(4) -> H-3(6) (475 nm), (1)G(4) -> F-3(4) (650 nm), F-3(2,3) -> H-3(6) (690 nm), and H-3(4) -> H-3(6) (803 nm) transitions, which indicated a two-photon absorption process. As for bio-labelling application, the results indicated that Yb3+ concentration was directly related to signal intensity. Conclusions: The intensity of positive conversion emissions depends directly on Yb3+ concentration. The biolabelling tests pointed to the potential application of these materials. The sample containing the highest amount of Yb3+ provided better results and was easier to detect than the standard sample. (AU) | |
| FAPESP's process: | 15/20298-0 - Obtention of luminescent LaNbO4:Ln (ln = Dy, TM, er and Yb) matrices prepared by spray pyrolysis process |
| Grantee: | Lucas Alonso Rocha |
| Support Opportunities: | Regular Research Grants |