**4. Comparison with Other Immunoassay Methods**

Compared with other studies on immunoassay of PAHs, this study has the following advantages: firstly, this is the first study to establish an ELISA method for the detection of PYR and BaP in aquatic products, because most of the PAHS ELISA methods developed in recent years focus on environmental samples, such as water (lake water, tap water, drinking water) and air [15,32,33]. Secondly, although no new hapten was designed in this study, a monoclonal antibody with high sensitivity that can recognize PYR and BaP simultaneously was obtained by synthesizing complete antigens with different coupling ratios. Scharnweber et al. took BaP as the object to synthesize hapten. The procedure of this synthesis method is complicated, and hazardous chemical reagents such as toluene and pyridine are used in the synthesis of hapten, so it is difficult to control its harm to the environment and human beings in the synthesis process [29]. Finally, compared with the commercially available BaP kit of American REAGEN Company, the detection limit of this study is lower, and the pretreatment method is simpler.
