Oxidation of benzene-diols proceeds through a one-electron abstraction to form a semi-quinone radical , and we reasoned that if a radical is formed during the process of generating optical modulations, highly reducing reagents should attenuate or eliminate these optical responses. Similarly, if electron transfer reactions occur, dissolved molecular oxygen could act as an electron sink or play a role as an intermediate in a putative electrochemical reaction, generating reactive oxygen species. We observed no attenuation in optical response in the presence of reducing reagents and reactive oxygen scavengers, consistent with the absence of oxidation from ELISA and HPLC measurements (Supplementary Fig. ). In sum, our findings indicate that redox reactions involving dissolved molecular oxygen or single electron transfers that generate radicals are unlikely to be present. Previous studies have similarly showed that reactive oxygen species are unlikely to be involved during catecholamine molecular recognition. We therefore conclude that although optical responses showed a strong correlation with the electrochemical properties of benzene-1,2-diols, the evidence indicates that the analytes themselves are not undergoing oxidation during the process of optical modulation of ssDNA-SWCNT conjugates.