Skip to content
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Publication Details
AFRICAN RESEARCH NEXUS
SHINING A SPOTLIGHT ON AFRICAN RESEARCH
biochemistry, genetics and molecular biology
Reagentless, reusable, ultrasensitive electrochemical molecular beacon aptasensor
Journal of the American Chemical Society, Volume 128, No. 1, Year 2006
Notification
URL copied to clipboard!
Description
A bifunctional derivative of the thrombin-binding aptamer with a redox-active Fc moiety and a thiol group at the termini of the aptamer strand was synthesized. The ferrocene-labeled aptamer thiol was self-assembled through S-Au bonding on a polycrystalline gold electrode surface and the surface was blocked with 2-mercaptoethanol to form a mixed monolayer. By use of a fluorescent molecular beacon, the effect of counterions on quadruplex formation was established. The aptamer-modified electrode was characterized electrochemically by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The modified electrode showed a voltammetric signal due to a one-step redox reaction of the surface-confined ferrocenyl moiety of the aptamer immobilized on the electrode surface In 10 mM N-(2-hydroxyethyl)piperazine-N′-2-ethanesuifonic acid (HEPES) buffer of pH 8.0. An increase in the DPV current signal was evident after blocking with 2-mercaptoethanol, effectively removing aptamer nonspecifically absorbed rather than bound to electrode surface or due to the formation of the aptamer-thrombin affinity interaction. The impedance measurement, in agreement with the differential pulse voltammetry (DPV), showed decreased Faradaic resistances in the same sequence, The "signal-on" upon thrombin association could be attributed to a change in conformation from random coil-like configuration on the probe-modified film to the quadruplex structure. The DPV of the modified electrode showed a linear response of the Fc oxidation signal to the increase in the thrombin concentration in the range between 5.0 and 35,0 nM with a linear correlation of r = 0.9988 and a detection limit of 0.5 nM. The molecular beacon aptasensor was amenable to full regeneration by simply unfolding the aptamer in 1.0 M HCI, and could be regenerated 25 times with no loss in electrochemical signal upon subsequent thrombin binding. © 2006 American Chemical Society.
Authors & Co-Authors
Radi, Abd Elgawad
Spain, Tarragona
Universitat Rovira I Virgili
Spain, Barcelona
Institució Catalana de Recerca I Estudis Avançats
Acero Sánchez, Josep Lluís
Spain, Barcelona
Institució Catalana de Recerca I Estudis Avançats
Baldrich, Eva
Spain, Barcelona
Institució Catalana de Recerca I Estudis Avançats
O’ Sullivan, Ciara K.
Spain, Barcelona
Institució Catalana de Recerca I Estudis Avançats
Egypt, New Damietta
Faculty of Science
Statistics
Citations: 513
Authors: 4
Affiliations: 3
Identifiers
Doi:
10.1021/ja053121d
ISSN:
00027863