Detection of natural bio-toxins using an improved design interdigital sensors

New types of interdigital sensors have been fabricated to investigate their sensing performance. New sensors have been fabricated using different method of manufacturing. Each manufacturing technique used different substrates. Due to different values of permittivity of different substrate, the capacitance values and corresponding impedance values are influenced by these substrates. The substrates variation was used to investigate the effect of substrate properties on sensing performance. The first design was fabricated on a Printed Circuit Board (PCB) material made from a FR-4; the second sensor design was fabricated using thick film on alumina. The third sensor was designed using thin-film (MEMS) technology and was fabricated on a glass substrate. The performances of the sensors were evaluated for different configurations of the electrode structures as well as dielectric materials. Initial experiments have been conducted to analyse the sensor´s performance with two peptide derivatives namely Sarcosine and Proline. These peptides are closely related to the target molecule of domoic acid, a natural toxin in seafood. This paper will highlight the design, analysis and fabrication of novel type of planar interdigital sensors. Impedance Spectroscopy detection technique has been used to analyse the sensors performance.