A Novel Gold Nanoparticle-Ionic Liquid Nanostructure Modified <i>Pleurotus Ostreatus</i> Based Microbial Biosensor System For Bisphenol A

The current study develops the first and novel gold nanoparticle-ionic liquid nanostructure modified microbial biosensor based on Pleurotus ostreatus for the sensitive determination of Bisphenol A. In the construction of the microbial biosensor, lyophilized P.ostreatus cells were modified with ionic liquid-cysteamine mixture on a gold electrode which was modified with 1,6-hexanedithiol and gold nanoparticle. The measurement principle of the biosensor is based on the detection of changes in current in a phosphate buffer system (pH 7.5, 50 mM and containing 5.0 mM K3[Fe(CN)6]) in the potential range of -0.2 to +0.6 V depending on the BPA concentration. In the optimization studies of the microbial biosensor; the most suitable ionic liquid-cysteamin ratio was 1 : 2 (v/v) and the incubation time of 1,6-hexanedithiol on the gold electrode was 6 hours. Optimum working conditions were determined to be pH:7.5, 100 mM potassium phosphate buffer, and 35 degrees C. In the characterization studies of the microbial biosensor, parameters such as linearity, interference effects of some substances on the microbial biosensor responses, repeatability, reproducibility and storage stability of the microbial biosensor were determined. The linear range of the biosensor was obtained 10-250 mu M. Limit of detection was determined to be 1.57 mu M and the response time was obtained 20 seconds. Real sample analysis was carried out by water samples that kept in plastic bottles for 6 months by using both the microbial biosensor and HPLC method.