Development of a new microbial biosensor based on conductive polymer/multiwalled carbon nanotube and its application to paracetamol determination

Abstract In this study, a new microbial biosensor based on Bacillus subtilis was developed for sensitive determination of paracetamol. The microbial biosensor was modified by using carboxylated multiwalled carbon nanotube (cMWCNT) and conductive polymer, polyaniline (PANI) in presence of glutaraldehyde on a gold working electrode. Paracetamol measurements by the microbial biosensor were carried out at 0.5 V applied potential with amperometric method. In the optimization studies of the microbial biosensor, the effect of (amount or concentration of) the bioactive layer components such as MWCNT, PANI, Bacillus sp. were carried out. In addition, working conditions of the microbial biosensor such as pH and temperature were also investigated. In the characterization studies of the biosensor some paramaters such as linearity, reproducibility, storage stability, substrat specificity and interference effect on the biosensor responses were determined. In the reproducibility experiments (n = 7), the average value, standard deviation, (SD) and coefficent of variation (CV%) were calculated to be 250.65 μM, ±1.55, 0.62% for 250 μM paracetamol concentration, consecutively. Detection limit was calculated as 2.9 μM by using visual evaluation mehod. In addition, paracetamol was carried out in drug samples by the developed biosensor.