Method for detecting mercury with pyrene functionalized silica nanoparticles

Patent metadata

Field	Value
Publication number	US-11435288-B1
Application number	US-202217745358-A
Country	US
Kind code	B1
Filing date	May 16, 2022
Priority date	May 16, 2022
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

A method for detecting mercury (Hg2+) ions in an aqueous solution is described. The method includes contacting the aqueous solution with a chemosensor to form a mixture; and monitoring a change in a fluorescence emission profile of the chemosensor in the mixture to determine the presence or absence of Hg2+ ions in the aqueous solution. The chemosensor includes pyrene silica nanoparticles where at least one pyrene is bonded to a surface of a silica nanoparticle through an amide bond with a formula of, pyrene-C(═O)NHR-silica nanoparticle, and where R is an alkyl chain.

First claim

The invention claimed is:

1. A method of detecting Hg 2+ ions in an aqueous solution, comprising:
contacting the aqueous solution with a chemosensor to form a mixture; and
monitoring a change in a fluorescence emission profile of the chemosensor in the mixture to determine a presence or absence of Hg 2+ ions in the aqueous solution;
wherein the chemosensor comprises pyrene silica nanoparticles having at least one pyrene bonded to a surface of a silica nanoparticle through an amide bond with a formula of pyrene-C(═O)NHR-silica nanoparticle;
wherein R is an alkyl chain.

2. The method of claim 1 , wherein R is —CH 2 CH 2 CH 2 —.

3. The method of claim 1 , wherein the pyrene silica nanoparticles have a uniform size distribution; and an average size of 30-50 nm.

4. The method of claim 1 , wherein the pyrene silica nanoparticles have a substantially spherical shape.

5. The method of claim 1 , wherein the pyrene silica nanoparticles have an amorphous structure.

6. The method of claim 1 , wherein the pyrene silica nanoparticles have a positively charged surface; and
a zeta potential of 35-45 mV.

7. The method of claim 1 , wherein the pyrene silica nanoparticles are agglomerated to form a mesoporous structure.

8. The method of claim 7 , wherein the elements Si, O, C, and N are homogeneously distributed throughout the mesoporous structure.

9. The method of claim 1 , wherein the pyrene silica nanoparticles have a BET surface area of 30-60 m 2 /g.

10. The method of claim 1 , wherein the pyrene silica nanoparticles have a total pore 15 volume of 0.25-0.4 cm 3 /g.

11. The method of claim 1 , wherein the pyrene silica nanoparticles have an average pore size of 20-30 nm.

12. The method of claim 1 , wherein the pyrene silica nanoparticles are stable up to 200° C.

13. The method of claim 1 , further comprising monitoring the change in the fluorescence emission profile of the chemosensor between 350-550 nm.

14. The method of claim 1 , wherein the change in the fluorescence emission profile is measured by the disappearance of a fluorescence band from 360 to 425 nm.

15. The method of claim 1 , wherein the change in the fluorescence emission profile is measured by the appearance of a fluorescence band from 400 to 525 nm.

16. The method of claim 1 , wherein the change in the fluorescence emission profile linearly correlates with the concentration of Hg 2+ in the aqueous solution.

17. The method of claim 1 , further comprising quantifying the change in the fluorescence emission profile to determine a concentration of Hg 2+ ions in the aqueous solution.

18. The method of claim 1 , wherein the chemosensor is selective for detecting Hg 2+ ions.

19. The method of claim 1 , wherein the aqueous solution further comprises at least one metal cation selected from the group consisting of Na + , K + , Ca 2+ , Mg 2+ , Ba 2+ , and Ag + ; and
the change in the fluorescence emission profile occurs only in the presence of Hg 2+ .

20. The method of claim 1 , wherein the limit of detection for Hg 2+ ions is 10 ppb.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Ali Shahid
• MANSHA Muhammad
• Khan Safyan Akram
• Baig Nadeem

Classifications

• G01N33/2028 Primary

  Metallic constituents · CPC title

• G01N31/22

  using chemical indicators (G01N31/02 takes precedence) · CPC title

• G01N21/6428 Primary

  Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53) · CPC title

• G01N2021/174

  either absorption-reflection or emission-fluorescence · CPC title