Creatinine biosensor and method of using the same

Patent metadata

Field	Value
Publication number	US-10000784-B2
Application number	US-201515509067-A
Country	US
Kind code	B2
Filing date	Sep 1, 2015
Priority date	Sep 8, 2014
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

This disclosure relates to creatinine biosensors and the uses thereof. More specifically, this disclosure describes potentiometric creatinine sensors which utilizes one or both of a type of enzyme capable of directly producing ammonium ions (NH4+) as a consequence of coming into contact with a liquid sample and an internal fill solution with a low free ammonium ion concentration.

First claim

What is claimed is:

1. A potentiometric biosensor, comprising:
an active electrode, wherein the active electrode is an Ammonium (NH 4 + ) ion-selective electrode and comprises an internal fill solution and a first membrane, the first membrane separating the internal fill solution from a liquid sample when the active electrode is inserted into the liquid sample, the first membrane containing a first type of enzyme capable of directly producing ammonium ions (NH 4 + ) as a consequence of coming into contact with the liquid sample and being devoid of a second type of enzyme;
an inactive electrode, wherein the inactive electrode is an Ammonium (NH 4 + ) ion-selective electrode and comprises the internal fill solution and a second membrane, the second membrane separating the internal fill solution from the liquid sample when the inactive electrode is inserted into the liquid sample, the second membrane being devoid of enzymes that are capable of directly producing ammonium ions (NH 4 + ) as a consequence of coming into contact with the liquid sample; wherein the first and the second membranes are ammonium ion-specific; and
the internal fill solution having a total ammonium ion concentration in the range of 1 to 10 mM and a free ammonium ion concentration of three or four orders of magnitude lower than the total ammonium ion concentration, wherein the total ammonium ion concentration includes complexed ammonium ions and free ammonium ions.

2. The potentiometric biosensor of claim 1 , wherein the first type of enzyme, when placed in contact with the liquid sample, reacts with creatinine present in the liquid sample to produce ammonium.

3. The potentiometric biosensor of claim 1 , wherein the first type of enzyme is one of creatinine iminohydrolase (CIH) or creatinine deimianase (CD).

4. The potentiometric biosensor of claim 1 , further comprising a voltmeter electrically coupled to the active electrode and the inactive electrode.

5. The potentiometric biosensor of claim 1 , wherein the free ammonium ion concentration is three orders of magnitude lower than the total ammonium ion concentration.

6. The potentiometric biosensor of claim 1 , wherein the free ammonium ion concentration is four orders of magnitude lower than the total ammonium ion concentration.

Assignees

• Siemens Healthcare Diagnostics Inc

Inventors

• Zhang Wei
• Zhang Jingzhong

Classifications

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C12Q1/002 Primary

  Electrode membranes · CPC title

• G01N27/26

  by investigating electrochemical variables; by using electrolysis or electrophoresis · CPC title

• C12Q1/005

  involving specific analytes or enzymes (including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence) · CPC title

• G01N27/3335 Primary

  the membrane containing at least one organic component (G01N27/3271 takes precedence; aspects concerning the enzyme reagent in enzyme electrodes C12Q1/001) · CPC title