Development and Application of a 1,8-Naphthalimide-Based Fluorescent Probe for Sensitive Detection of Hydrogen Sulfide in Human Blood Serum

Abstract

This work implies the preparation, structural and fluorescent characterization, and application of the 1,8-naphthalimide-based fluorescent probe for H₂S detection in human blood serum. The mechanism of fluorescent detection of H₂S is based on the reduction of the azide group, as the chemical reactive site, in the fluorescent probe structure, to the amino group. Compound 2 possesses another important structural motif, ethanolamine moiety, which modulates physicochemical properties. The synthetic pathway for the preparation of compound 2 is consisted of two reaction steps, and the target compound was prepared with a yield of 56%. The prepared compound 2 was characterized using ¹H and ¹³C NMR spectroscopy and elemental analysis. During the fluorescence spectra measurements, several influences on fluorescence intensity were investigated, including pH, time dependence, selective response, and influence of H₂S concentration. The detection limit was calculated, which was 0.16 μmol L⁻¹. For examination of the application of compound 2 for H₂S detection in real samples, compound 2 was successfully applied for H₂S detection in human blood serum. The concentration of H₂S in the human serum sample was 16.2 μmol L⁻¹.The accuracy of H₂S determination in human blood serum samples is confirmed by the standard addition method and UV-Vis spectrophotometry method using methylene blue.