New types of planar interdigital sensors, were fabricated using three different methods. These sensors were used to assess different chemicals related to food poisoning. The sensors were designed to have different configurations and were constructed on different substrates. The substrate 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 FR4 fiberglass; the second sensor design was fabricated using thick film on alumina. The third sensor was designed using thin-film [microelectromechanical systems (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 analyze 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. Experiments with endotoxin have been presented and the possibility of extending the sensors for detection of chemicals responsible for food poisoning has been discussed. Initial investigation on the sensors' performance based on Impedance Spectroscopy method is reported in this paper.