Sensitive fluorescence detection of mercury(ii) in aqueous solution by the fluorescence quenching effect of MoS₂ with DNA functionalized carbon dots

Abstract

A rapid and sensitive fluorescent sensor based on the MoS nanosheet/DNA/carbon dot nanoassembly has been developed towards the detection of mercury(ii) present in environmental samples. Bio-carbon dots (CDs) having strong fluorescence maxima at 451 nm were synthesized via one-step treatment with honey under low temperature carbonization. These CDs were nearly spherical with good size distribution and excellent monodispersity, and the average sizes of CD were around 2-4 nm as evidenced from transmission electron microscopy. The conjugation of DNA strands on the surface of the carbon dots provided an efficient fluorescent probe. The fluorescence of the MoS nanosheet/DNA/carbon dot nanoassembly enhanced gradually with the increase in the concentration of Hg ions and the detection limit was found to be 1.02 nM. Furthermore, the fluorescence intensity was found to be linear with the concentration of Hg ions in the range from 0 to 10 nM and their respective coefficient of determination was found to be 0.93676 and 0.98178. The present MoS nanosheet/DNA/carbon dot nanoassembly is highly selective toward Hg ions over a wide range of metal ions tested.

Sensitive Hg2+ Sensing via Quenching the Fluorescence of the Complex between Polythymine and 5,10,15,20-tetrakis(N-methyl-4-pyridyl) Porphyrin (TMPyP)

“…A colorimetric method for Hg 2+ determination through platinum nanoparticles with limit of detection 8.5 pM and a linear range from 0.01 to 4 nM has been reported by Aragay et al [ 18 ]. MoS 2 nanosheet/DNA/carbon dot-based fluorescence method has been reported to detect Hg 2+ [ 19 ]. However, most of the methods were based on synthesized nanometer materials such as nanoparticle, quantum dots, nanosheet, which were hard to be modified.…”

Carbon-based quantum particles: an electroanalytical and biomedical perspective

“…Most of the procedures proposed for metal ions detection are based on fluorescence quenching by metal ions such as the detection of Hg 2+ , [98][99][100][101] Cu 2+ , 102 Fe 3+ , 103 Al 3+ , 104 and Ag + . 103,104,[105][106][107][108] In this detection scheme, metal ions interact with CQDs via surface bonding, which results in the formation of electron-hole recombination via an electron transfer process and changes the fluorescence intensity, used as measurable response signal. 109 CQDs-COOH interact or example with high affinity with Hg 2+ to create new non-radiative hole-pairs, leading to fluorescence quenching.…”

Two-dimensional nanomaterials for Förster resonance energy transfer–based sensing applications

“…The LOD of the MoS 2 -based assay was calculated to be 500 pm and 5 μm for DNA and adenosine, respectively. Since then, dozens of researchers have reported the development of MoS 2 -DNA-based FRET sensors for the detection of various targets, such as the nucleic acids [74][75][76][77][78][79][80][81][82][83][84][85], proteins [86][87][88][89][90][91][92][93][94][95], metal ions [96,97], small molecules [52,86,[98][99][100][101][102][103][104], enzyme activity [105], and others [106]. These sensors mainly take advantage of the fluorescence-quenching capability and different affinity of MoS 2 to ssDNA and ssDNA-target combination, enabling easy preparation, single-step, and rapid detection.…”