CdTe/CdS-MPA quantum dots as fluorescent probes to label yeast cells: synthesis, characterization and conjugation with Concanavalin A

Author(s):Show less -

Kato, Ilka T. ; Santos, Camila C. ; Benetti, Endi ; Tenorio, Denise P. L. A. ; Cabral Filho, Paulo E. ; Sabino, Caetano P. ; Fontes, Adriana ; Santos, Beate S. ; Prates, Renato A. ; Ribeiro, Martha S. ; Parak, WJ ; Yamamoto, K ; Osinski, M

• Document type: Journal article
• Source: COLLOIDAL NANOCRYSTALS FOR BIOMEDICAL APPLICATIONS VII; v. 8232, p. 6-pg., 2012-01-01.

Abstract

Candida albicans is the most frequent human opportunistic pathogenic fungus and one of the most important causes of nosocomial infections. In fact, diagnosis of invasive candidiasis presents unique problems. The aim of this work was to evaluate, by fluorescence image analysis, cellular labeling of C. albicans with CdTe/CdS quantum dots conjugated or not to concanavalin A (ConA). Yeast cells were incubated with CdTe/CdS quantum dots (QD) stabilized with mercaptopropionic acid (MPA) (emission peak at 530 nm) for 1 hour. In the overall study we observed no morphological alterations. The fluorescence microscopic analysis of the yeast cells showed that the non-functionalized QDs do not label C. albicans cells, while for the QD conjugated to ConA the cells showed a fluorescence profile indicating that the membrane was preferentially marked. This profile was expected since Concanavalin A is a protein that binds specifically to terminal carbohydrate residues at the membrane cell surface. The results suggest that the QD-labeled Candida cells represent a promising tool to open new possibilities for a precise evaluation of fungal infections in pathological conditions. (AU)

• FAPESP's process: 10/13313-9 - Development of methodologies for photodynamic therapy applications on fungal infections
• Grantee: Martha Simões Ribeiro
• Support Opportunities: Regular Research Grants