Effects of gamma radiation exposure on PANI-Fe(X) -Ni(1−X) (X = 0.2,0.4,0.6,0.8) nanocomposite thin film for Leptospira detection

Abstract

The aim of this research is to develop a PANI-Fe-Ni nanocomposite thin film sensor for pathogenic and saprophytic Leptospira detection. In this study, Leptospira detection is distinguished at concentrations of 108 CFU ml−1, 107 CFU ml−1, 106 CFU ml−1, and 105 CFU ml−1 respectively. PANI-Fe-Ni nanocomposite is spin-coated on a glass substrate to form a thin film sensor. The samples were later exposed to different doses of gamma radiation which were 15 kGy and 30 kGy. This is done to analyze the effects of gamma radiation on the sensitivity of the sensor. The morphology of the thin film was characterized using scanning electron microscope (SEM) and atomic force microscopy (AFM). The sensor performances were measured using current-voltage (I-V) and electrochemical impedance spectroscopy (EIS). The measurement was taken by immersing the sensor into the Leptospira solution. According to the result, the surfaces of the thin film shrink to form agglomeration due to the gamma radiation. Besides that, observation under atomic force microscopy (AFM) shows increment in the grain size of of PANI-Fe-Ni nanocomposite. Furthermore, surface roughness of thin film sensor increased when Fe quantity increased. The study found that there is an increase in current and voltage readings when the thin film sensor is exposed to the Leptospira bacteria proving that the sensor works. It was deduced that samples of PANI-Fe0.8-Ni0.2 were the most suitable to be used as thin film sensor. Current and voltage tests showed that samples that were not exposed to radiation are more sensitive.