Development of Coumarin-Based Probe for Spectrofluorometric Lead Determination in the Human Plasma: Exploring an Association With Otitis Media

Chronic otitis media poses a significant global health challenge, particularly burdening low socioeconomic areas, notably in developing nations. Despite its prevalence, the role of lead in chronic otitis media remains largely overlooked. This study introduces an innovative spectrofluorometric technique for highly sensitive lead detection in human plasma samples at the nano-level. The method capitalizes on the interaction between lead ions and 7,8-dihydroxy-4-phenylcoumarin, generating a distinct fluorescent product. This complex exhibit modified fluorescence characteristics compared to free 7,8-dihydroxy-4-phenylcoumarin, emitting at 505 nm when excited at 330 nm. This shift, accompanied by an increase in fluorescence intensity, enables precise lead quantification even within complex plasma matrices. Validation confirmed a consistent linear relationship within the 200–4000 ng/mL range. Application of the validated method revealed elevated lead levels in plasma samples from chronic otitis media patients compared to healthy controls. These findings suggest a potential link between lead exposure and chronic otitis media development, though further research is warranted for confirmation. This research underscores the importance of considering lead's impact on chronic otitis media etiology and progression, especially in vulnerable populations.