Colorimetric Detection of Mercuric Ion (Hg²⁺) in Aqueous Media using DNA‐Functionalized Gold Nanoparticles

Abstract

Color is everything: Hg2+ in aqueous media is detected by the formation of thymidine–Hg2+–thymidine coordination complexes, which raises the melting temperature of the DNA‐hybridized gold nanoparticle probes and thus the temperature at which the probes disperse and effect a purple‐to‐red color change. The method has very high sensitivity and selectivity, and it provides a simple and fast colorimetric readout (see picture).

Incorporation of the fluoride induced SiO bond cleavage and functionalized gold nanoparticle aggregation into one colorimetric probe for highly specific and sensitive detection of fluoride

“…Various metal ions were detected by monitoring the color changes occurring upon aggregation of ligand-functionalized AuNPs through specific molecular interactions [26][27][28][29][30]. However, studies on colorimetric anion recognition and sensing anions by AuNPs are limited [31][32][33][34][35][36].…”

Metal‐Induced Specific and Nonspecific Oligonucleotide Folding Studied by FRET and Related Biophysical and Bioanalytical Implications

“…[25,26] To manage the mercury contamination problem, many sensors have been developed. [27] In particular, a large number of fluorescent, [15,[28][29][30] colorimetric, [31,32] and electrochemical sensors [33,34] have been designed based on the Hg II -thymine binding. In the original paper by Ono et al, [15] the DNA shown in Figure 1A was labeled with a 6-carboxyfluorescein (FAM) and a dark quencher (4-(4-dimethylaminophenyl) diazenylbenzoic acid, Dabcyl), respectively on the two ends.…”

Hg2+ detection using a phosphorothioate RNA probe adsorbed on graphene oxide and a comparison with thymine-rich DNA

“…[11][12][13][14][15] While this interaction is highly specific for Hg 2+ , it is strongly influenced by buffer conditions such as pH, temperature, ionic strength, and anion species, 16,17 making it difficult for detection in real sample matrix. Another strategy relies on RNA-cleaving DNAzymes.…”