Oxytetracycline (OXT) is an important with widespread use antibiotic. But, like in the case of other antibiotics, its overuse fuels the rise of the problem of antibiotic resistance.
In this context, there is a clear need for the development of new, fast and sensitive analytical methods capable of performing in field analysis. Electrochemical sensors, like electrochemical aptasensors are viable solution for this [1].
The aim of our work was the developemnt of an aptasensor for OXT, using as a starting platform carbon-based screen printed electrodes (C-SPE), modified with Au-based nano/microstructures. These platforms were imagined and used due to their relatively lower cost compared to Au-based screen printed electrodes, and also to test the influence of the arhitecture of the Au nano/microstructures on the analytical performance of the aptasensor. As a biomimetic element, we used a thiolated deoxyribonucleic acid (DNA) aptamer, labelled with ferrocene.
The Au-based platforms and all the steps involved in the aptasensor development were electrochemically characterized, both indirectly using ferrocene and Ferro/ferricyanide redox probes and directly based on the electrochemical signal of the Au structures and on the signal of the labelled aptamer. The arhitecture of the Au structures were investigated using the scanning electron microscopy technique.
In conclusion, the creation and characterization of new Au-based nano/microstructures on C-SPE was carried out. The resulting analytical platforms were selected based on their influence on the immobilization of the aptamer and on the analytical performance, one of them being chosen as the starting point for the development of the final aptasensor.
Acknowledgements: This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CCCDI-UEFISCDI, project number ERANET-RUS-PLUS-PLASMON-ELECTROLIGHT/46/2018, within PNCDI III. GS thanks UMF for the internal grant number 2461/71/17.01.2020. OH thanks to the Romanian Ministry of Education and Research, CNCS - UEFISCDI, project number PN-III-P1-1.1-PD-2019-0631, within PNCDI III.
- Y. Li, J. Tian, T. Yuan, P. Wang, and J. Lu, Sensors Actuators, B Chem., vol. 240, pp. 785–792, 2017, doi: 10.1016/j.snb.2016.09.042.
