Detection of Urea by Conductivity-regulated Bipolar Electrochemiluminescence

doi:10.7503/cjcu20250101

Abstract

Abstract:

In this study， a bipolar electrochemiluminescence（BPE-ECL） sensing platform based on the regulation of conductivity was constructed for the detection of urea. An independent sensing cell and a reporting cell were built on the patterned BPE， and ruthenium bipyridine/tri-n-propylamine was used as the source of ECL. When urea at different concentrations is present in the sensing cell， urease specifically catalyzes the decomposition of urea， generating ions that promote an increase in the conductivity. Based on the charge balance of BPE， the ECL intensity from the reporting cell increases. Meanwhile， the ECL intensities increase following the enhancement of urea concentrations. Therefore， a BPE-ECL platform based on the regulation of conductivity was established for the detection of urea. Under optimal conditions， this sensing platform exhibits a good linear relationship for urea in the range of 10 nmol/L to 1 mmol/L， and the limit of detection is 0.19 nmol/L（S/N=3）. The sensing platform was further applied to spiked recovery detection in human urine samples， showing good accuracy and anti-interference ability. This sensing strategy not only eliminates the need for exogenous electroactive indicators， but also effectively avoids the interference of complex biological samples with the signal reaction through the sensing-signal separation of BPE.

Key words: Bipolar electrode（BPE）, Electrochemiluminescence（ECL）, Conductivity regulation, Sensing-signal separation, Urea

CLC Number:

O657

TrendMD:

YANG Bifang, GUO Xiaoge, DAI Xiaohui, YANG Weiqiang, NI Jiancong. Detection of Urea by Conductivity-regulated Bipolar Electrochemiluminescence[J]. Chem. J. Chinese Universities, 2025, 46(8): 20250101.

Figures/Tables 7

References 17

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Method	Sensing strategy	Linear range	LOD	Ref.
Colorimetry	Sensing platform for detecting urea based on the change of pH caused by the catalytic decomposition of urea by urease	0.02—0.4 mmol/L	0.005 mmol/L	［25］
Fluorescence	Fluorescent sensing platform based on the interactions among the fluorophore APMP， urease， and urea	2—80 mmol/L	73 μmol/L	［4］
Electrochemistry	Electrochemical sensor based on the influence of urea⁃decomposition products on the surface charge of nanochannels	25 pmol/L—2.8 μmol/L	12 pmol/L	［5］
Electrochemiluminescence	ECL sensor based on electrode surface modification， leveraging the synergistic effect of ECL and molecularly imprinted polymer	45 μmol/L—19.5 mmol/L	15.0 μmol/L	［26］
BPE⁃ECL	Sensing platform based on changes in solution conductivity	10 nmol/L—1mmol/L	0.19 nmol/L	This work

Method	Sensing strategy	Linear range	LOD	Ref.
Colorimetry	Sensing platform for detecting urea based on the change of pH caused by the catalytic decomposition of urea by urease	0.02—0.4 mmol/L	0.005 mmol/L	［25］
Fluorescence	Fluorescent sensing platform based on the interactions among the fluorophore APMP， urease， and urea	2—80 mmol/L	73 μmol/L	［4］
Electrochemistry	Electrochemical sensor based on the influence of urea⁃decomposition products on the surface charge of nanochannels	25 pmol/L—2.8 μmol/L	12 pmol/L	［5］
Electrochemiluminescence	ECL sensor based on electrode surface modification， leveraging the synergistic effect of ECL and molecularly imprinted polymer	45 μmol/L—19.5 mmol/L	15.0 μmol/L	［26］
BPE⁃ECL	Sensing platform based on changes in solution conductivity	10 nmol/L—1mmol/L	0.19 nmol/L	This work