Electrical detection of cancer biomarker using aptamers with nanogap break-junctions

Epidermal growth factor receptor (EGFR) is a cell surface protein overexpressed in cancerous cells. It is known to be the most common oncogene. EGFR concentration also increases in the serum of cancer patients. The detection of small changes in the concentration of EGFR can be critical for early dia...

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Bibliographic Details
Published in:Nanotechnology 2012-07, Vol.23 (27), p.275502-275502
Main Authors: Ilyas, Azhar, Asghar, Waseem, Allen, Peter B, Duhon, Holli, Ellington, Andrew D, Iqbal, Samir M
Format: Article
Language:English
Subjects:
Aptamers, Nucleotide - chemistry
Biomarkers, Tumor - analysis
Biosensing Techniques - instrumentation
Biosensing Techniques - methods
Conductometry - instrumentation
Equipment Design
Equipment Failure Analysis
Microelectrodes
Nanotechnology - instrumentation
Receptor, Epidermal Growth Factor - analysis
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Summary:Epidermal growth factor receptor (EGFR) is a cell surface protein overexpressed in cancerous cells. It is known to be the most common oncogene. EGFR concentration also increases in the serum of cancer patients. The detection of small changes in the concentration of EGFR can be critical for early diagnosis, resulting in better treatment and improved survival rate of cancer patients. This article reports an RNA aptamer based approach to selectively capture EGFR protein and an electrical scheme for its detection. Pairs of gold electrodes with nanometer separation were made through confluence of focused ion beam scratching and electromigration. The aptamer was hybridized to a single stranded DNA molecule, which in turn was immobilized on the SiO2 surface between the gold nanoelectrodes. The selectivity of the aptamer was demonstrated by using control chips with mutated non-selective aptamer and with no aptamer. Surface functionalization was characterized by optical detection and two orders of magnitude increase in direct current (DC) was measured when selective capture of EGFR occurred. This represents an electronic biosensor for the detection of proteins of interest for medical applications.
ISSN:0957-4484
1361-6528
DOI:10.1088/0957-4484/23/27/275502