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An interference-free and rapid electrochemical lateral-flow immunoassay for one-step ultrasensitive detection with serum.
- Source :
-
The Analyst [Analyst] 2014 Mar 21; Vol. 139 (6), pp. 1420-5. - Publication Year :
- 2014
-
Abstract
- Point-of-care testing (POCT) of biomarkers in clinical samples is of great importance for rapid and cost-effective diagnosis. However, it is extremely challenging to develop an electrochemical POCT technique retaining both ultrasensitivity and simplicity. We report an interference-free electrochemical lateral-flow immunoassay that enables one-step ultrasensitive detection with serum. The electrochemical-chemical-chemical (ECC) redox cycling combined with an enzymatic reaction of an enzyme label is used to obtain high signal amplification. The ECC redox cycling involving Ru(NH3)6(3+), enzyme product, and tris(3-carboxyethyl)phosphine (TCEP) depends on pH, because the formal potentials of an enzyme product and TCEP increase with decreasing pH although that of Ru(NH3)6(3+) is pH-independent. With consideration of the pH dependence of ECC redox cycling, a noble combination of enzyme label, substrate, and product [β-galactosidase, 4-amino-1-naphthyl β-D-galactopyranoside, and 4-amino-1-naphthol, respectively] is introduced to ensure fast and selective ECC redox cycling of the enzyme product along with a low background level. The selective ECC redox cycling at a low applied potential (0.05 V vs. Ag/AgCl) minimizes the interference effect of electroactive species (L-ascorbic acid, acetaminophen, and uric acid) in serum. A detection limit of 0.1 pg mL(-1) for troponin I is obtained only 11 min after serum dropping without the use of an additional solution. Moreover, the lateral-flow immunoassay is applicable to the analysis of real clinical samples.
- Subjects :
- Biosensing Techniques economics
Biosensing Techniques instrumentation
Electrochemical Techniques economics
Equipment Design
Humans
Immunoassay economics
Limit of Detection
Point-of-Care Systems economics
Electrochemical Techniques instrumentation
Immunoassay instrumentation
Troponin I blood
Subjects
Details
- Language :
- English
- ISSN :
- 1364-5528
- Volume :
- 139
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- The Analyst
- Publication Type :
- Academic Journal
- Accession number :
- 24482801
- Full Text :
- https://doi.org/10.1039/c3an02328a