An Ultrasensitive Real-time Immuno-polymerase Chain Reaction Assay for Detection of Tetrabromobisphenol A in PM2.5 Particles Using Functionalized Nanoprobes

Tetrabromobisphenol A (TBBPA), a type of brominated flame retardant, is widely distributed in the environment. In this work, different TBBPA antigens and polyclonal anti-TBBPA antibody (pAb-TBBPA) were prepared, and on the basis of this, an ultrasensitive real-time immuno-polymerase chain reaction for TBBPA detection using functionalized nanoprobes (FNPs-IPCR) was developed. Gold nanoparticles modified with thiol-capped DNA and pAb-TBBPA were prepared as antibody-DNA conjugates, and the signal intensity of the immunoassay was greatly enhanced. Under optimal conditions, the proposed immunoassay was used to detect TBBPA with a linearity ranging from 1 pg L−1 to 10 ng L−1, and the limit of detection was 0.62 pg L−1. The recovery was 89.2%–107.4% and the coefficient of variation was 3.17%–7.73%. The FNPs-IPCR assay was highly selective and sensitive. Finally, the detection results of TBBPA in PM2.5 samples were consistent with those from high performance liquid chromatography, indicating that the FNPs- IPCR method is suitable for trace TBBPA screening in environmental samples.