Au nanoparticle conjugation for impedance and capacitance signal amplification in biosensors

Analytical Chemistry
Jianbin WangIan I Suni

Abstract

Amplification of the electrochemical impedance and capacitance signals in a biosensor is demonstrated for the model fluorescein/anti-fluorescein system. Following immobilization of fluorescein onto Au through formation of a self-assembled monolayer, goat anti-fluorescein conjugated with 10-nm Au nanoparticles is introduced into the system. This results in an increase in the capacitance of approximately 400 nF/cm(2), whereas no change can be observed for goat anti-fluorescein without the Au nanoparticle conjugate. An even greater sensitivity is obtained by introduction of a redox probe, [Fe(CN)6]3-/4-, whereby the charge-transfer resistance (R(ct)) is reduced to approximately 25% of its original value. This allows construction of high-sensitivity electrochemical impedance biosensors at a single low frequency, where the signal is sensitive to the interfacial R(ct). This change in the electrochemical impedance signal upon binding to goat anti-fluorescein conjugated with Au nanoparticles can be attributed to the much higher electrochemical activity of Au surfaces relative to the underlying organic layer.

Citations

Apr 29, 2014·Bioprocess and Biosystems Engineering·Zhili GongXiangyou Wang
Sep 14, 2010·Analytical Sciences : the International Journal of the Japan Society for Analytical Chemistry·Zhan WuRu-Qin Yu
Apr 17, 2008·Analytical and Bioanalytical Chemistry·F Lisdat, D Schäfer
Jul 20, 2010·Annual Review of Analytical Chemistry·Byoung-Yong Chang, Su-Moon Park
Aug 30, 2011·Journal of Virological Methods·Ronghui WangYanbin Li
Jun 28, 2011·Analytical Biochemistry·Xiaodong CaoSongqin Liu
Feb 18, 2014·Biosensors & Bioelectronics·Amr M MahmoudAbebaw B Jemere
Apr 10, 2018·Nanotechnology·Hojjat Alizadeh ZeinabadSeyed Mehdi Boutorabi
Jan 1, 2016·Comprehensive Reviews in Food Science and Food Safety·Yun Wang, Joelle K Salazar
Nov 11, 2008·Langmuir : the ACS Journal of Surfaces and Colloids·Bo ChenRichard A Gross
Sep 25, 2008·Chemical Reviews·Amir Zabet-Khosousi, Al-Amin Dhirani
Dec 17, 2008·Analytical Chemistry·Cheng FangNarayanan Balasubramanian

❮ Previous
Next ❯

Related Concepts

Related Feeds

Biosensor Development & Applications

Biosensor development and applications describe recent progress in biosensor development and their applications in the field of antibiotics and metabolic engineering. Discover the latest research on biosensor development and applications in this feed.