García-Gancedo, Luis and Iborra Grau, Enrique and Clement Lorenzo, Marta and Olivares Roza, Jimena and Zhu, Z. and Flewitt, A.J. and Milne, W.I. and Ashley, G.M. and Luo, J.K. and Zhao, X.B. and Lu, J.R.
Solidly Mounted Resonators with Carbon Nanotube Electrodes for Biosensing Applications.
In: "2011 Joint Conference of the IEEE International Frequency Control and the European Frequency and Time Forum, FCS", 01/05/2011 - 05/05/2011, San Francisco, EE. UU.. ISBN 978-1-61284-111-3. pp. 1-5.
The work reported here shows a direct experimental comparison of the sensitivities of AlN solidly mounted resonators (SMR)-based biosensors fabricated with standard metal electrodes and with carbon nanotube electrodes. SMRs resonating at frequencies around 1.75 GHz have been fabricated, some devices using a thin film of multi-wall carbon nanotubes (CNTs) as the top electrode material and some identical devices using a chromium/gold electrode. Protein solutions with different concentrations were loaded on the top of the resonators and their responses to mass-load from physically adsorbed coatings were investigated. Results show that resonators using CNTs as the top electrode material exhibited higher frequency change for a given load due to the higher active surface area of a thin film of interconnecting CNTs compared to that of a metal thin film electrode and hence exhibited greater mass loading sensitivity. It is therefore concluded that the use of CNT electrodes on resonators for their use as gravimetric biosensors is viable and worthwhile.