Yüzey Plazmon Rezonans Sensörü ile Sentetik Reseptörler Kullanılarak Sütte Bulunan Benzilpenisilinin Tayini

Abstract

Antibiotic residues in food products, drinking water and the environment cause the emergence of antibiotic-resistant bacterial strains, disruption of the normal ecological balance, and serious health consequences, including an increased incidence of allergic reactions. For these reasons, the detection of these antibiotic residues in food and the environment is vital for the protection of public health. In this study, selective and sensitive detection of benzylpenicillin antibiotic from both aqueous solution and milk samples was performed by surface plasmon resonance sensor prepared using molecular imprinting technique. For this purpose, benzylpenicillin imprinted poly (hydroxyethyl methacrylate-graphene oxide-N-methacryloyl-L-phenylalanine) (MIP-GO) SPR sensor was produced. Following the charaterization studies of sensor surface, benzylpenicillin detection was performed by MIP-GO SPR sensor with 0.021 ppb detection limit and a linear correlation of 0.9665 for the 1-100 ppb concentration range of benzylpenicillin. Selectivity studies were carried out to show that the MIP-GO SPR sensor selectively detects the target molecule benzylpenicillin, and it was determined that the MIP-GO SPR sensor detected the target benzylpenicillin molecule 8.16 times more selectively than amoxicillin and 14.04 times more selectively than ampicillin. To examine the imprinting efficiency, non-imprinted poly (hydroxyethyl methacrylate-graphene oxide-N-methacryloyl-L-phenylalanine) (NIP-GO) SPR sensor was prepared using the same polymerization recipe without the addition of benzylpenicillin molecule. By comparing the MIP-GO SPR sensor with the NIP-GO SPR sensor, the imprinting efficiency was determined as IF: 11.06. Since graphene oxide (GO) was added to increase the surface iv plasmon resonance signal response, control experiments were performed by a poly (hydroxyethyl methacrylate-graphene oxide-N-methacryloyl-L-phenylalanine) (MIP) SPR sensor prepared without adding GO to examine this effect. MIP-GO, NIP-GO and MIP SPR sensors were characterized by fourier-transform infrared spectrophotometer, atomic force microscopy and contact angle measurements. Repeatability studies of MIP-GO SPR sensor were performed for 25 ppb benzylpenicillin concentration and statistically analyzed. The percent relative standard deviation (RSD) of intraday-assays of less than 1.0% indicated a negligible loss of benzylpenicillin detection ability even after four adsorption-desorption cycles with the same sensor. As a real food sample, the benzylpenicillin amount spiked into the milk sample with 6.25 ppb final benzylpenicillin concentration and also unspiked milk sample was determined by MIP-GO SPR sensor. High-performance liquid chromatography (HPLC) experiments were carried out for validation studies.