Filling two needs with one deed: Differential sensing of anthrax biomarker dipicolinic acid and bovine serum albumin using binary ensemble based on 1,8-naphthalimide Schiff base and cationic surfactant

Abstract

Keeping in mind the severities of anthrax disease caused by bacteria Bacillus anthracis and side effects of abnormal levels of a nonmetalloprotein bovine serum albumin (BSA), their early diagnosis was highly required. The existing lanthanide based sensors for their detection are not up to the mark due to their potential disadvantages of genetic toxicity, bio-migration, supply shortages, low atom utilization and poor stability. To address these issues, a binary ensemble OHNP@CTAB was fabricated in aqueous medium by encapsulation of 1,8-naphthalimide derived Schiff base (OHNP) in the micelles of a cationic surfactant CTAB. Significant changes were observed in the absorption and emission spectrum of OHNP@CTAB in the presence of DPA and BSA mainly due to electrostatic interaction among positively charged receptor and negatively charged guest species. Limit of detection (LOD) values of OHNP@CTAB towards DPA and BSA were calculated to be 1.19 and 0.11 µM, respectively from fluorescence spectral titration data. Moreover, the binary ensemble OHNP@CTAB efficiently detected BSA and DPA in real samples viz. packaged milk, gulkand and candy.