High sensitivity and selectivity microwave biosensor using biofunctionalized differential resonant array implemented in LTCC for Escherichia coli detection
Ilona Piekarz, Jakub Sorocki, Sabina Górska, Heike Bartsch, Artur Rydosz, Robert Smolarz, Krzysztof Wincza, Sławomir Gruszczyński
Abstract
A novel method for label-free detection of Escherichia coli relying on microwave sensing is proposed. A transmission-type differential resonator array biosensor covered with polyclonal anti-Escherichia coli antibodies is introduced providing a robust response with high sensitivity for detecting bacteria presence due to resonant operation combined. The high selectivity is given by the presence of specific bacteria-binding antibodies. Low-Temperature Co-Fired Ceramics technology is proposed to be used for implementation to take advantage of its quasi-three-dimensional fabrication capability. The proposed sensing structure operates in a frequency range of 4 – 6 GHz with five distinct resonances increasing the probability of bacteria detection presence. The developed sensor was experimentally validated by measurements of various concentrations of Escherichia coli along with measurement of a non-specific high concentration of Lactobacillus rhamnosus LOCK 0919. The obtained results prove the performance and suitability of the proposed biosensor for biomedical applications.