Fluorescence-linked immunosorbent assay for detection of phenanthrene and its homolog

A competitive fluorescence-linked immunosorbent assay (FLISA) was developed using rhodamine B isothiocyanate (RBITC) as the model fluorescent dye conjugate monoclonal antibody (McAb) for detection of Phe and its homolog (acenaphthene, fluorene, fluoranthene, pyrene and indeno [1,2,3-cd] pyrene) in water samples. The detection range of the assay for Phe was from 2.10 to 91.95 ng/mL. The limit of detection was 1.05 ng/mL, which was approximately 2-fold lower than that of traditional ic-ELISA. Compared with traditional ic-EUSA, more than 70 min was saved because of only one immunoreaction step was needed to accomplish the assay. The average recoveries of Phe and its homolog from domestic water, contaminated water and natural water were 100.7%, 100.8% and 101.2% respectively. The accuracy and precision of the developed FLISA were validated with GC-MS/MS. There were good correlation between the two methods from tap water, contaminated water and river water samples were 0.9994, 0.9935 and 0.9967, respectively. The results suggested that the proposed FLISA could be a potential alternative format for rapid, sensitive, and quantitative detection of Phe and its homolog in environmental water.