Improved detection limits of bacterial endotoxins using new type of planar interdigital sensors

Abstract

New types of planar interdigital sensors were fabricated by photolithography and etching techniques on a Silicon/Silicon Dioxide (Si/SiO2) wafer (single side polished). The sensors were then coated with APTES (3-aminopropyltrietoxysilane) a cross linker used to bind Polymyxin B (PmB) molecules on electrodes surface. PmB is an antimicrobial peptide produced by the Gram-positive bacterium-Bacillus which has specific binding properties to Lipopolysaccharide (LPS). This paper will discuss the fabrication process, coating and immobilization procedures and analysis of sensors' performance based on Impedance Spectroscopy method. The sensor sensitivity was compared to standard ToxinSensor Chromogenic LAL Endotoxin Assay Kit for verification. © 2012 IEEE.