DNA-modified graphene quantum dots as a sensing platform for detection of Hg²⁺in living cells

Abstract

A facile method for detection of Hg2+in living cells based on DNA modified graphene quantum dots.

Development of Graphene Quantum Dots-Based Optical Sensor for Toxic Metal Ion Detection

“…The change in fluorescence intensity of DNA-GQDs and Hg 2+ concentration showed a linear relationship over the range 0.001 µM to 10 µM. The calculated limit of detection for Hg 2+ was equal to 0.25 nM [49].…”

Graphene quantum dots as smart probes for biosensing

“…Due to efficient quantum connement and edge effects, GQDs show outstanding luminescence performance, such as stable light emitting, high quantum yield, good photostability, easy modulation and excellent biocompatibility. 10,71 Various GQDbased PL probes have been reported for the detection of metal ions, 40,60,[72][73][74][75][76][77][78][79][80] small molecules [81][82][83][84][85][86] and biomacromolecules, [87][88][89][90][91][92] and even design of detection platforms. 93,94 Metal ions are necessary for normal function of cells and the survival of organisms.…”

Fluorescence Microscopy—An Outline of Hardware, Biological Handling, and Fluorophore Considerations

“…The detection of mercuric ions (Hg 2+ ) in living cells is an important pursuit given the high toxicity they impart on the body, which can lead to kidney, liver, and brain damage [ 222 ]. GQDs coated with thymine-rich DNA have been reported to accurately detect Hg 2+ in HeLa cells, whereby Hg 2+ strongly coordinates with thymine residues to create a rigid hairpin on the GQD surface, ultimately decreasing the GQD emission at 460 nm by approximately 90%, as observed using confocal microscopy [ 223 ]. Another example of intracellular Hg 2+ detection utilised GQDs conjugated with rhodamine fluorophores to create a FRET ‘turn-on’ system in the presence of Hg 2+ ( Figure 5 ).…”