Electrochemical sensor for lead detection

Patent metadata

Field	Value
Publication number	US-11125717-B2
Application number	US-201916255486-A
Country	US
Kind code	B2
Filing date	Jan 23, 2019
Priority date	Jan 23, 2018
Publication date	Sep 21, 2021
Grant date	Sep 21, 2021

Abstract

A sensor for detecting lead in an aqueous solution includes a copper working electrode, a counter electrode, a power supply for applying underpotential deposition of lead onto the copper electrode from the aqueous solution, a measuring device for providing measurement of a hydrogen evolution reaction (HER) current on the Pbupd-modified electrode, and a means for correlating the degree of suppression of the HER current to Pbupd coverage to determine the lead coverage and lead concentration of the solution.

First claim

Having described the invention, we claim:

1. A method of detecting lead in an aqueous sample, the method comprising:
immersing a sensor in an aqueous sample, the sensor including a copper working electrode and a counter electrode;
biasing the copper working electrode at a cathodic potential effective to facilitate underpotential deposition of a lead monolayer on a surface of the copper working electrode from the aqueous sample; and
measuring a hydrogen evolution reaction (HER) current of the lead covered working electrode to determine the lead coverage and the lead concentration of the sample.

2. The method of claim 1 , wherein the lead coverage and the lead concentration of the sample is determined by comparing the measured HER current of the lead covered working electrode to control value.

3. The method of claim 2 , wherein the control value is a HER baseline current on lead-free working electrode.

4. The method of claim 3 , further comprising stripping of the lead underpotential deposition layer formed to recover a lead-free, bare copper surface of the copper working electrode; and
measuring the HER current on the bare copper working electrode.

5. The method of claim 1 , wherein the counter electrode comprises gold, platinum, palladium, silver, carbon, or alloys thereof.

6. The method of claim 1 , wherein the sensor further comprises a reference electrode.

7. The method of claim 1 , wherein the copper working electrode has a needle-like dendritic surface profile.

8. The method of claim 1 , wherein the needle-like dendritic surface profile of the copper working electrode is defined by an underlying Zn dendrite potentiostatic electroplate.

9. A method of detecting lead in an aqueous sample, the method comprising:
immersing a sensor in an aqueous sample, the sensor including a copper working electrode and a counter electrode;
biasing the copper working electrode at a cathodic potential effective to facilitate underpotential deposition of a lead monolayer on a surface of the copper working electrode from the aqueous sample; and
measuring a hydrogen evolution reaction (HER) current of the lead covered working electrode by comparing the measured HER current of the lead covered working electrode to a HER baseline current on lead-free working electrode to determine the lead coverage and the lead concentration of the sample.

10. The method of claim 9 , further comprising stripping of the lead underpotential deposition layer formed to recover a lead-free, bare copper surface of the copper working electrode; and measuring the HER current on the bare copper working electrode.

11. The method of claim 9 , wherein the counter electrode comprises gold, platinum, palladium, silver, carbon, or alloys thereof.

12. The method of claim 9 , wherein the sensor further comprises a reference electrode.

13. The method of claim 9 , wherein the copper working electrode has a needle-like dendritic surface profile.

14. The method of claim 13 , wherein the needle-like dendritic surface profile of the copper working electrode is defined by an underlying Zn dendrite potentiostatic electroplate.

Assignees

• Univ Case Western Reserve

Inventors

• Akolkar Rohan
• Liu Xinyu
• Venkatraman Kailash

Classifications

• G01N27/42 Primary

  Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte · CPC title

• G01N27/4166 Primary

  measuring a particular property of an electrolyte · CPC title

• G01N33/1813

  Specific cations in water, e.g. heavy metals · CPC title