br Materials and methods br Results and discussion

Materials and methods
Results and discussion
Conclusions In summary, the Au@SiO2 based lateral flow sandwich immunoassay for fast detection of EBN-specific glycoprotein has been firstly established by using nanocomposites as signaling-labels and synthesized EBN-specific Oligomycin Complex sale as recognition biomolecules. The detection limit was estimated as 7.02 ng mL−1 which was equal to 0.7 g of purified glycoprotein in 100 μL buffer. There was no interferences from some normally used adulterants, meaning the promising application of the test strips in EBN authentication. Compared to instrumental methods and other molecular biological techniques, the lateral flow sandwich immunoassay provided sensitive and specific detection of EBN-specific glycoprotein within 30 min without devices and complicated procedure. EBN glycoprotein lateral flow immunoassay could be employed for on-site authentication and quality assessment of EBN. Future work will aim to investigate the commercial EBN products on the market, and extract different EBN-specific glycoproteins from EBN products originated from different geographical areas. The lateral flow test strip for each specific glycoprotein analysis in ground EBN product can be developed. Thus, the fast identification and verification of geographic origin of EBN products will be accomplished.
Conflicts of interest
Acknowledgments This study was supported by University-Industry Cooperation Project (NO. 2016Y4006) from Fujian Provincial Department of Science and Technology, central guidance on the development of local science and technology (NO. 2017L3015) from Fujian Provincial Department of Science and Technology, and Education & Research Projects of Young Scientists (NO. JAT170195) from Fujian Provincial Department of Education.
Introduction Chinese annual production of cultured oysters amounts to 4.7 × 106 tons in 2017 (G.Y. Wang et al., 2018, W.X. Wang et al., 2018). Crassostrea gigas is one species of widely consumed oysters along the coastal regions in China. However, as marine filter-feeders with poor mobility, oysters have the ability to accumulate heavy metals such as Cd from seawater, which becomes a great concern among consumers because of the toxicity of Cd. A previous study has reported the concentrations of trace metals including Cd in oysters of Chinese coastal waters. The results showed that Crassostrea gigas contained hazardous concentrations of Cd, which was higher than the permissible limit of food in China (2 mg/kg fw) (Lu et al., 2017). Removing Cd in marine products is significant for reducing the risk of eating them. The work could be classified into decreasing Cd content in marine organisms during aquaculture and removal of Cd in seafood processing after harvest. Some studies have focused on Cd removal or decreasing the bioaccessibility of Cd in food processing, for example, cooking process, disposal of scallop broth, utilization of enzymatic hydrolysate and soaking of dry meat (Atungulu et al., 2007; Houlbrèque et al., 2011; Suprapti et al., 2016; Hu et al., 2017). Meanwhile, consistent research interests exist in Cd depuration during aquaculture. When different Cd concentrations in oyster can be attributed to different farming environment conditions such as salinity, season, pH, and temperature, it is an alternative strategy to adjust the farming environment to reduce the Cd bioaccumulation of oysters. Numerous studies have explored the influences of some environmental factors on Cd content in aquatic products. Higher levels of salinity resulted in lower Cd concentration in tissues of Crassostrea gigas (Sun et al., 2018). The Cd elimination in Crassostrea virginica is enhanced with elevated temperature or the higher concentration of humic acid (Van Dolah et al., 1987). It was also observed that Cd accumulation was influenced by the uptake of Zn in Australian tropical rock oysters (Munksgaard et al., 2017).