Nanoplataforma entre complexo nitrosilo de rutênio e pontos de carbono

Abstract

Carbon dots (CDs) are particles nanoscale semiconductors. The more explored feature of this type of nanomaterial is its light emission properties, besides to having low toxicity, allowing its application as biocompatible cellular markers. Its high solubility in aqueous medium gives the opportunity to be applied in physiological medium. Also noteworthy is its potential research focus as a nanoplatform in bioimaging systems, for follow-up studies and drug release profiles. Therefore, this work objectives to develop a methodology for preparing CDs through the hydrothermal process, using commercial bovine gelatine as the raw material. In addition, the work describes methods of spectroscopy and interaction of CDs and nitrosyl ruthenium complex as nitric oxide donor, of the type [RuII(NH.NHq-COOH)(tpy)(NO)](PF6)3 (RuBDQ). The results that obtained the demonstration and characterization of CDs, demonstrated that the aqueous solution, exhibited the maximum emission in the region of 400 nm at pH = 7. The aqueous suspension of the CDs stays stable until 30 days at 5ºC. The fluorescence emission profiles are dependent on the excitation wavelength, and this work demonstrated a higher fluorescence intensity when excited at 320 nm. The quantum fluorescence yield indicates a correlation with temperature, causing a decrease in fluorescence intensity with an increase in temperature. An atomic force microscopy indicates that CDs are about 10 nm in diameter in particle size. The zeta potential demonstrated a negative charge of -21mV for CDs, or gives them the possibility of interacting with positively charged complexes. The interaction mechanism between CDs and the RuBDQ complex, can be dynamic or static, depending on the temperature conditions. The thermodynamic parameters demonstrated that the interaction between the two species is an electrostatic interaction.