Abstract: A novel biomimetic sensor for the potentiometric transduction of oxytetracycline is presented. The artificial host was imprinted in methacrylic acid and/or acrylamide based polymers. Different amounts of molecularly imprinted and non-imprinted polymers were dispersed in different plasticizing solvents and entrapped in a poly(vinyl chloride) matrix. Only molecularly-imprinted based sensors allowed a potentiometric transduction, suggesting the existence of host-guest interactions. These sensors exhibited a near-Nernstian response in steady state evaluations; slopes and detection limits ranged 42-63 mV/decade and 2.5-31.3 μg/mL, respectively. Sensors were independent from the pH of test solutions within 2-5. Good selectivity was observed towards glycine, ciprofloxacin, creatinine, acid nalidixic, sulfadiazine, cysteine, hydroxylamine and lactose. In flowing media, the biomimetic sensors presented good reproducibility (RSD of ± 0.7%), fast response, good sensitivity (65 mV/decade), wide linear range (5.0 x 10-5-1.0 x 10-2 mol/L), low detection limit (19.8 μg/mL), and a stable baseline for a 5 x 10-3 M citrate buffer (pH 2.5) carrier. The sensors were successfully applied the analysis of drugs and urine. This work confirms the possibility of using molecularly-imprinted polymers as ionophores for organic ion recognition in potentiometric transduction
Author keywords: Molecularly-imprinted sensors, Potentiometry, ion-selective electrodes, Oxytetracycline, Flow-injection analysis.