Abstract
Objective: The objective of this study was to develop a new biosensor system based on nanoparticle to determine penicillin in pharmaceuticals.
 Methods: The characterization and optimization of the potentiometric penicillin biosensor (PB) were prepared by using synthesized surface-dependent and surface-independent ZnO nanoparticles named ZnO nanorods and chitosan were carried out. It was preferred ZnO nanorod because of its electrical, optical, physical and photocatalyst properties, biocompatibility and non-toxicity in the construction of the penicillin biosensor.
 Results: The operating range was obtained as 10-1-10-3M, the optimum buffer concentration was 10 mmol, optimum pH was 7.4 and the optimum temperature was 25 °C for the PB. The PB has advantages in terms of short response time, long enough shelf life, cheap, and easy elaborate.
 Conclusion: Whether the biosensor can be used to determine penicillin and accurately measure penicillin, the amount of penicillin in a commercial pharmaceutical preparation named Alfoxil was successfully made by using our prepared penicillin biosensor.