NANOCOMPOSITE OF POLYANILINE AND MAGNETIC ALLOYS (Ag-Fe, g-Co, Ag-Ni) THIN FILMS BASED AMPEROMETRIC SENSOR SYNTHESIZED BY LOW HEAT TREATMENT (300OC) FOR E. COLI DETECTION

Abstract

The use of magnetic metals in sensor application has been widely attracted. The combination of one of the three main magnetic metals (Fe, Ni, Co) with antibacterial material, Ag and conducting polymer, PANI will produce a better characteristic of thin film for microbial sensor application. PANI-Ag-Fe, PANI-Ag-Ni and PANI-Ag-Co nanocomposite thin films were synthesized via sol-gel method with annealing at 300oC. The films were characterized by XRD, AFM and UV-Vis to study the crystallite structure, surface morphology and internal structural property. Amperometric sensor performance was conducted by I–V measurement with and without incubated in E. coli. XRD analysis confirm the face-centered cubic of Ag, Fe, Co and Ni crystal with the crystallite size around 8 – 11 nm. AFM images show the surface of PANI-Ag-Ni thin film has the highest roughness but smallest grain size than PANI-Ag-Fe and PANI-Ag-Co. UV-Vis absorbance band show the maximum absorption peak is around 420 – 500 nm. The sensor performance from I – V measurements show that PANI-Ag-Ni thin film sensor produce the highest sensitivity towards E. coli followed by PANI-Ag-Co and PANI-Ag-Fe.