Investigation on sensitized chemiluminescence systems and their mechanism for five fluoroquinolones

Abstract

The novel chemiluminescence (CL) reaction systems were established for lomefloxacin (LMFX), ofloxacin(OFLX), norfloxacin (NFLX), gatifloxacin (GAFX) and enoxacin (ENX). The sensitized CL emission mechanism was investigated for the five systems by comparing the fluorescence emission with CL spectra. For LMFX–Ce(IV)–S 2O 3 2−–H 2SO 4 and OFLX–Ce(IV)–S 2O 4 2−–H 2SO 4 systems, the CL intensity is enhanced through intermolecular energy transfer from the excited SO 2 * to LMFX and OFLX. For NFLX–Ce(IV)–S 2O 4 2−–HNO 3 system, the sensitized CL is based on intermolecular energy transfer from the excited SO 2 * to NFLX oxide. For Eu 3+–GAFX–Ce(IV)–S 2O 4 2−–HCl and Dy 3+–ENX–Ce(IV)–S 2O 3 2−–H 2SO 4 systems, the CL spectra are from the narrow characteristic emission at 590, 619 and 649 nm of Eu 3+* ( 5D 0 → 7F 1, 5D 0 → 7F 2, 5D 0 → 7F 3) and at 482 and 578 nm of Dy 3+ ( 4F 9 → 6H 15/2, 4F 9 → 6H 13/2) through intermolecular energy transfer from the excited SO 2 * to GAFX and ENX, followed by intramolecular energy transfer from GAFX * to Eu 3+ and ENX * to Dy 3+. The conditions of CL emission were investigated and optimized. The proposed five enhanced CL systems have good linearity, higher sensitivity, precision and potential capability for residue analysis of studied analytes in foods and biological samples.