Session: Current Topics in Biological Chemistry:

Detection of specific nucleic acids is crucial for the analysis of homeostatic and pathological expressions of individual genes into proteins. The established use of fluorescent nucleobases requires meticulous design and incorporation of either a canonical or non-canonical nucleobase into a nucleic acid. Using the fluorescent nano allotrope, carbon dots, an alternative method for facile detection of guanosine was examined. Carbon dots are a highly modifiable nanomaterial with characteristic optical properties and notable biocompatibility. They are classically used for cellular imaging and have recently been applied in nanozymatic systems and hybrid nanomaterial development. Here, a novel dual-fluorescent carbon dots system was employed. These modified carbon dots absorb and fluoresce at blue and red wavelengths that undergo characteristic changes in the presence of guanosine. The absorbance signature is a combination of the individual absorbance spectra of the nucleoside and carbon dots. While the fluorescence intensities varied in the presence of guanosine in a concentration-dependent manner. This effect was due to electronic communication between guanosine and fluorescence core and surface states of the carbon dots. Using a fluorescence quenching assay, a linear response was observed in the micromolar range (20 - 100 uM). Data indicate that carbon dots are valuable probes for nucleic acid building blocks.

Dr. Sanela Martic

Assistant Professor, Trent University

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