Development of Phage Immuno-Loop-Mediated Isothermal Amplification Assays for Organophosphorus Pesticides in Agro-products

Abstract

Two immuno-loop-mediated isothermal amplification assays (iLAMP) were developed by using a phage-borne peptide that was isolated from a cyclic eight-peptide phage library. One assay was used to screen eight organophosphorus (OP) pesticides with limits of detection (LOD) between 2 and 128 ng mL–1. The iLAMP consisted of the competitive immuno-reaction coupled to the LAMP reaction for detection. This method provides positive results in the visual color of violet, while a negative response results in a sky blue color; therefore, the iLAMP allows one to rapidly detect analytes in yes or no fashion. We validated the iLAMP by detecting parathion-methyl, parathion, and fenitrothion in Chinese cabbage, apple, and greengrocery, and the detection results were consistent with the enzyme-linked immunosorbent assay (ELISA). In conclusion, the iLAMP is a simple, rapid, sensitive, and economical method for detecting OP pesticide residues in agro-products with no instrumental requirement.

Loop-Mediated Isothermal Amplification Assay (LAMP): A Rapid Tool for Diagnosis of Foodborne and Zoonotic Pathogens: A Review

“…But based on the literature recommendation, the performance of the LAMP assay developed was found to be equal or superior to the best available PCR assay for the detection of celery in food products (Hua et al, 2014). …”

“…Hua et al (2014) developed iLAMP which is a rapid, sensitive, and economical method for detecting Organophosphorus (OP) pesticides and their residues in food and the environment and in future can be used for the detection of other small molecules. OP pesticides are considered as hazardous substances because of their toxicity to nonpests and bioaccumulation and biological magnification in the environment.…”

Magnetic-Immuno-Loop-Mediated Isothermal Amplification Based on DNA Encapsulating Liposome for the Ultrasensitive Detection of P-glycoprotein

“…Recently, LAMP has attracted great interest, because of its unique advantages of under isothermal conditions (60–65 °C), high specificity and sensitivity using a set of six specially designed primers and a BstDNA polymeras within 2 hours 14 – 16 . Due to such advantages, LAMP has become a powerful tool for nucleic acid amplification and it has already been applied widely in pathogen detection 17 , tumor detection 18 , organophosphorus pesticides 19 and embryo sex identification 20 . However, to the best of our knowledge, no investigator has reported on magnetic immuno-LAMP assay for trace amounts of protein analysis based on DNA-encapsulating liposomes.…”

Competitive and noncompetitive phage immunoassays for the determination of benzothiostrobin

“…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]. …”