pH-Sensitive fluorescent sensor for Fe(III) and Cu(II) ions based on rhodamine B acylhydrazone: Sensing mechanism and bioimaging in living cells

resumo

Spirocyclic rhodamine derivatives have great potential to be used as fluorescent sensors. Rho-damine B hy-drazide (RBH) and its derivatives have been employed to detect various analytes. The interactions of a sensor with an analyte might result in the protonation or hydrolysis of the sensor. Understanding these processes is useful for developing new sensors with improved characteristics. In this work, the performance of rhodamine B acylhydrazone (RBA) as a sensor for Fe3+ and Cu2+ ions is evaluated. In the presence of these ions, RBA un-dergoes protonation and the spirolactam ring opening. The ring opening renders the dye colored and fluorescent. RBA is then hydrolyzed to RBH leading to the decay of the absorbance in the visible range. The protonation and hydrolysis of RBA are acid-catalyzed, and metal ions contribute to these processes by lowering pH. Metal ions, unlike hydrogen ions, catalyze the transformation of RBH into rhodamine B and a phenanthrenone derivative. These products exhibit emission bands in the visible and near-infrared ranges, respectively. The obtained results can be applied to a variety of sensors based on rhodamines and Schiff bases. RBA can be employed for bio-imaging. RBA quickly penetrates into cells, localizes in the organelles with acidic pH, probably in lysosomes, persists there for a long time, and gives bright fluorescence in the visible range. Cell incubation with Cu2+ ions produces fluorescence in the near-infrared range. RBA can be used as a multifunctional fluorescent biosensor to visualize cell compartments with acidic pH and detect Cu2+ ions in living cells.

palavras-chave

HIGHLY SELECTIVE FLUORESCENT; OXIDATIVE STRESS; FLUOROGENIC PROBE; CHEMOSENSOR; FE3+; IRON; CHEMODOSIMETER; CU2+; HG2+; RECOGNITION

categoria

Chemistry

autores

Belko, N; Maltanava, H; Lugovski, A; Ferreira, RAS; Correia, SFH; Shabunya, P; Fatykhava, S; Tabolich, A; Kulahava, T; Bahdanava, A; Ferreira, M; Tedim, J; Poznyak, S; Samtsov, M

Grupos

G1 - Materiais Porosos e Nanossistemas
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos

Projectos

Eco-friendly corrosion protective coatings based on smart nanotechnology platforms for a circular economy (COAT4LIFE)

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

agradecimentos

This work was supported by the state program of scientific research of the Republic of Belarus "Photonics and Electronics for Innovation" (subprogram 1.1, task 1.6) , the state program of scientific research of the Republic of Belarus "Convergence" (subprogram 11.3, task 3.03.6) , the Belarusian Republican Foundation for Fundamental Research (grant no. H21M-073) , and the Polish National Agency for Academic Exchange within the scope of PROM2020 program. This project has received funding from the European Union's Horizon 2020 research and inno- vation programme under the Marie Sk l odowska-Curie grant agreement no. 101007430. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020, and LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) . The authors thank the Center for Analytical and Spectral Measure- ments of the B.I. Stepanov Institute of Physics for measuring fluores- cence excitation and emission spectra and the Elionics Laboratory of the A.N. Sevchenko Institute of Applied Physical Problems for measuring UV-Vis absorption spectra.