%0 Journal Article %1 citeulike:780934 %A Xu, D. %A Xu, D. %A Yu, X. %A Liu, Z. %A He, W. %A Ma, Z. %C Department of Biochemistry, Beijing Institute of Radiation Medicine, Beijing 100850, China. xudk@nic.bmi.ac.cn %D 2005 %J Anal Chem %K aptamer surface electrochemistry %N 16 %P 5107--5113 %R 10.1021/ac050192m %T Label-free electrochemical detection for aptamer-based array electrodes. %U http://dx.doi.org/10.1021/ac050192m %V 77 %X An electrochemical impedance spectroscopy method of detection for aptamer-based array electrodes is reported in which the binding of aptamers immobilized on gold electrodes leads to impedance changes associated with target protein binding events. Human IgE was used as a model target protein and incubated with the aptamer-based array consisting of single-stranded DNA containing a hairpin loop. To increase the binding efficiency for proteins, a hybrid modified layer containing aptamers and cysteamine was fabricated on the photolithographic gold surface through molecular self-assembly. Atomic force microscopy analysis demonstrated that human IgE could be specifically captured by the aptamer and stand well above the self-assembled monolayer (SAM) surface. Compared to immunosensing methods using anti-human IgE antibody as the recognition element, impedance spectroscopy detection could provide higher sensitivity and better selectivity for aptamer-modified electrodes. The results of this method show good correlation for human IgE in the range of 2.5-100 nM. A detection limit of 0.1 nM (5 fmol in a 50-microL sample) was obtained, and an average of the relative standard deviation was <10%. The method herein describes the first label-free detection for arrayed electrodes utilizing electrochemical impedance spectroscopy.

@article{citeulike:780934, abstract = {An electrochemical impedance spectroscopy method of detection for aptamer-based array electrodes is reported in which the binding of aptamers immobilized on gold electrodes leads to impedance changes associated with target protein binding events. Human IgE was used as a model target protein and incubated with the aptamer-based array consisting of single-stranded DNA containing a hairpin loop. To increase the binding efficiency for proteins, a hybrid modified layer containing aptamers and cysteamine was fabricated on the photolithographic gold surface through molecular self-assembly. Atomic force microscopy analysis demonstrated that human IgE could be specifically captured by the aptamer and stand well above the self-assembled monolayer (SAM) surface. Compared to immunosensing methods using anti-human IgE antibody as the recognition element, impedance spectroscopy detection could provide higher sensitivity and better selectivity for aptamer-modified electrodes. The results of this method show good correlation for human IgE in the range of 2.5-100 nM. A detection limit of 0.1 nM (5 fmol in a 50-microL sample) was obtained, and an average of the relative standard deviation was <10%. The method herein describes the first label-free detection for arrayed electrodes utilizing electrochemical impedance spectroscopy.}, added-at = {2006-07-31T20:01:51.000+0200}, address = {Department of Biochemistry, Beijing Institute of Radiation Medicine, Beijing 100850, China. xudk@nic.bmi.ac.cn}, author = {Xu, D. and Xu, D. and Yu, X. and Liu, Z. and He, W. and Ma, Z.}, biburl = {https://www.bibsonomy.org/bibtex/26df571f37298fc4a07f93c555995235e/biblio24}, citeulike-article-id = {780934}, comment = {xudk@nic.bmi.ac.cn}, doi = {10.1021/ac050192m}, interhash = {cde352182645fcf5ab3bda4425d94623}, intrahash = {6df571f37298fc4a07f93c555995235e}, issn = {0003-2700}, journal = {Anal Chem}, keywords = {aptamer surface electrochemistry}, month = {August}, number = 16, pages = {5107--5113}, priority = {2}, timestamp = {2006-07-31T20:01:51.000+0200}, title = {Label-free electrochemical detection for aptamer-based array electrodes.}, url = {http://dx.doi.org/10.1021/ac050192m}, volume = 77, year = 2005 }