Graphene oxide-based electrochemical activation of ethionamide towards enhanced biological activity

Balaji B Mulik; Sambhaji T Dhumal; Vijay S Sapner; Naziya N M A Rehman; Prashant P Dixit; Bhaskar R Sathe

doi:10.1039/c9ra06681k

Graphene oxide-based electrochemical activation of ethionamide towards enhanced biological activity

RSC Adv. 2019 Nov 1;9(61):35463-35472. doi: 10.1039/c9ra06681k. eCollection 2019 Oct 31.

Authors

Balaji B Mulik¹, Sambhaji T Dhumal¹, Vijay S Sapner¹, Naziya N M A Rehman², Prashant P Dixit², Bhaskar R Sathe¹

Affiliations

¹ Department of Chemistry, Dr Babasaheb Ambedkar Marathwada University Aurangabad 431004 Maharashtra India bhaskarsathe@gmail.com.
² Department of Microbiology, Dr Babasaheb Ambedkar Marathwada University Aurangabad, Sub-Campus Osmanabad MH 413501 India.

Abstract

The electrochemical behavior of ethionamide (ETO) was investigated on GO (∼500 nm) using the linear sweep voltammetric (LSV) technique at the sweep rate of 10 mV s^-1 in 1 M PBS buffer solution, and the characteristic anodic signal was examined at 0.240 V over the potential range of -0.4 to 1 V vs. SCE. However, linearity was observed with the increase in scan rate (2-300 mV s^-1) and concentration of ETO (1 μM to 100 mM), suggesting that the process involved diffusion-controlled electron transfer. The results also exhibited excellent current and potential stability, limit of detection (LOD 1.33) and limit of quantification (LOQ 4.4) at optimized experimental conditions. This electrochemical oxidation method was successfully applied in the complete oxidation of ETO to its oxidized form, which was further confirmed by high resolution mass spectroscopy (HRMS) and Fourier transform infrared (FTIR) spectroscopic measurements. Interestingly, the comparative biological evaluation of ETO and ETO-O (oxidised form) showed good enhancement in the activity of oxidised ETO against some Gram-negative pathogens, such as E. aerogenes, S. abony, S. boydii, and E. coli.