Naked eye sensing of toxic metal ions in aqueous medium using thiophene‐based ligands and its application in living cells

Abstract

Thiophene-based diimine (R1) and monoimine (R2) were synthesized in a single step, and their cation binding affinity was tested using colorimetric and UV-vis spectral studies. R1 selectively shows a colorimetric turn-on response for Pb(2+), Hg(2+) ions and colorimetric turn-off with Sn(2+) ions, and R2 shows visual response for Cu(2+) and Hg(2+) over other examined metal ions in aqueous medium. R1 forms 1:1 complex with Pb(2+), Hg(2+), and Sn(2+) and exhibits fluorescence quenching, whereas R2 shows 2:1 complex with Hg(2+), Cu(2+) and shows fluorescence enhancement. The structural and electronic properties of the sensors and their metal complexes were also investigated using Density Functional Theory calculations. R2 was also successfully demonstrated as a fluorescent probe for detecting Cu(2+) ions in living cells.

Determination of Mercury Ions in Aqueous Medium and Urine Sample Using Thiocarbohydrazide Based Sensor

“…The reduction in the absorption intensity from 0.35 a.u to 0.15 a.u for both the metal ions is compatible with the reported literature [47] . Thus, a minimum limit of detection as calculated using equation approved by IUPAC (LOD=3 σ/k) was found to be 27×10 −9 M and 0.16×10 −6 M for Hg 2+ and Cu 2+ ions respectively which is comparable to the values reported in the literature [13–35,39] …”

“…[11][12] Several sensors for the mercury, based on organic molecules and polymers have been reported in the literature. This includes use of coumarin, [13,14] hydroxyl chromones, [15] triazole, [16,17] benzimidazole, [18,19] benzothiadiazole, [20,21] thiophene, [22,23] porphyrin, [24,25] naphthalenediimide, [26,27] naphthyridine, [28,29] naphthalimides, [29,30] BODIPY, [31,32] 1-(2-aminoethyl)thioureas, [33] and dansylamides [34] groups to create optical probes that can work in organic or aqueous medium with a detection range of 10 À 5 to 10 À 10 M. Cleavage of the spirolactam ring in the rhodamine derivatives forms the basis of many Hg 2 + ion sensors. [35] The use of phenyl ethers for the detection of various cations and anions has recently been demonstrated.…”

“…Aqueous solubility of organic molecules is an additional challenge that limits the application of sensors in real life, environmental and biological samples. Many studies have been reported that use a mixture of organic solvent (MeCN, [14,23,28–30] THF [39] or Ethanol [32] ) and water in a ratio ranging from 1 : 1 to 4 : 1 to detect Hg 2+ ions. There are also reports where probes were able to detect Hg 2+ ions in an aqueous range of hundred to ninety percent.…”

A highly fluorescent zinc complex of a dipodal N-acyl hydrazone as a selective sensor for H2PO4− ions and application in living cells

“…[35][36][37][38] Utilizing the strong affinity of phosphate ions towards Zn 2+ ions, recently Shi et al 39 41 Small molecule synthesis is always welcome, because they can be synthesized in a single step which avoids the problems like high cost, disposal of hazardous chemicals and solvents. With the extension of our research in the field of chemosensors using a dipodal receptor, [42][43][44][45] The theoretically calculated energy values were compared with the absorbance corresponding to R1 and R1-Zn 2+ complexes obtained from the UV-vis spectrum.…”

Optical sensor: a promising strategy for environmental and biomedical monitoring of ionic species

“…Schiff base Cu 2+ sensorUdhayakumari et al149 reported thiophene-based diimine 79 and monoimine 80(Fig. Schiff base Cu 2+ sensorUdhayakumari et al149 reported thiophene-based diimine 79 and monoimine 80(Fig.…”