Simultaneous development of both competitive and noncompetitive immunoassays for 2,2′,4,4′-tetrabromodiphenyl ether using phage-displayed peptides

Abstract

Twenty-five phages that selectively bind to a monoclonal antibody (Mab) 1H2 specific to 2,2',4,4'-tetrabromodiphenyl ether (BDE47) in the absence or presence of BDE47 have been selected from phage-display libraries containing cyclic 7-mer, linear 7-mer, and linear 12-mer randomized peptides. Competitive and noncompetitive enzyme-linked immunosorbent assays (ELISA) for BDE47 were developed by using a clone C7-1 specific to the BDE47-free Mab 1H2 and a clone XC7-8 specific to the BDE47-bound Mab 1H2, respectively. The half-maximum signal inhibition concentration (IC50) of the competitive phage ELISA and the half-maximum signal enhancement concentration (EC50) of the noncompetitive phage ELISA for BDE47 were 6.8 ng mL(-1) and 4.2 ng mL(-1), respectively. The noncompetitive phage ELISA showed higher cross-reactivity with BDE28, BDE99, and BDE100 than the competitive one, ranging between 1.3 and 6.5 % versus 0.3 and 0.8 %. Recoveries of the competitive and the noncompetitive phage ELISAs for BDE47 in sewage sludge and fillet samples were 96-124 % and 97-120 %, respectively. The results of the two types of phage ELISAs for BDE47 in the real-world samples agreed well with a gas chromatography/electron capture detector-ion trap mass spectrometer method.

Selection of phage-displayed peptides for the detection of imidacloprid in water and soil

“…A few studies have successfully employed peptide display to select binders for small molecules, for example, fluorophores [29], 2,4,6-trinitrotoluene [30], microcystin-LR [31], and paclitaxel (Taxol) [32]. We recently presented a panning strategy for the integrated selection of phage-borne peptides binding to either a particular ligand-antibody complex or a ligand-free antibody, leading to the development of assays for the targeted ligand 2,2 0 , 4,4 0 -tetrabromodiphenyl ether (BDE47) [33]. To explore the possibility of expanding the scope of this technology to environmental monitoring, in the current study we used commercially available random peptide libraries to screen peptide ligands specific for imidacloprid, providing an economical and convenient method to isolate specific peptides directly binding small molecules.…”

Small Molecular Contaminant and Microorganism Can Be Simultaneously Detected Based on Nanobody-Phage: Using Carcinogen Aflatoxin and Its Main Fungal Aspergillus Section Flavi spp. in Stored Maize for Demonstration

“…Generally, if nanobody phages specific for small molecular contaminants are available, the simultaneous detection would become not a challenge. Currently, nanobody phages specific for various contaminants such as zearalenone (Wang et al, 2016), ochratoxin A (Liu et al, 2014), deoxynivalenol (Tu et al, 2012), fumonisin B 1 (Shu et al, 2019), synthetic microorganics (Wang et al, 2013a;Hua et al, 2015;Ding et al, 2017), citrinin (CIT) (Xu et al, 2015), and microcystins (MCs) (Xu et al, 2018) are available. Therefore, using the new method developed here, the simultaneous detection for these small molecular contaminants and their related microorganisms could also be realized.…”

Competitive and noncompetitive phage immunoassays for the determination of benzothiostrobin

“…Phage-displayed peptide libraries have been a powerful tool for isolating peptides that specifically bind to analyte-free antibodies (peptidomimetics) or analyte-bound antibodies (anti-immunocomplex peptides) [9]. Analyte peptidomimetics can be used as surrogate competing haptens to accelerate the development of heterologous immunoassays.…”

“…Analyte peptidomimetics can be used as surrogate competing haptens to accelerate the development of heterologous immunoassays. Some investigators have successfully obtained analyte peptidomimetics that can be used as a competing hapten for low-molecular-weight compounds from phage display peptide libraries, and the analyte peptidomimetics show better sensitivity than chemical synthesis of homologous and heterologous competing haptens [3, 9–18]. Anti-immunocomplex phage peptides can specifically recognize an analyte-bound antibody to enhance the affinity and selectivity of the primary antibody because of the formation of a ternary complex, which translates into an improved noncompetitive immunoassay for a low-molecular-weight compound [8].…”

“…Anti-immunocomplex phage peptides can specifically recognize an analyte-bound antibody to enhance the affinity and selectivity of the primary antibody because of the formation of a ternary complex, which translates into an improved noncompetitive immunoassay for a low-molecular-weight compound [8]. Although only eight low-molecular-weight compounds (brominated diphenyl ether 47, clomazone, malachite green, leucomalachite green, gibberellin, 2,2′,4,4′-tetrabromodiphenyl ether, phenoxybenzoic acid, molinate and atrazine) have been successfully detected by noncompetitive immunoassays based on anti-immunocomplex phage peptides, each presented better performance than the corresponding conventional competitive immunoassays [8, 9, 19–24]. Additionally, real-time polymerase chain reaction and loop-mediated isothermal amplification have been successfully used to detect low-molecular-weight chemicals by using phage-displayed peptides because of the unique characteristic that phage-displayed peptides can be connected to nucleic acids (single stranded DNA) [3, 25, 26].…”