An Integrated Real‐time Electrochemical LAMP Device for Pathogenic Bacteria Detection in Food

Abstract

A novel, integrated, real‐time electrochemical loop‐mediated isothermal amplification (LAMP) device for pathogen detection in food was developed. The electrochemical LAMP device for detection of the vt gene in E. coli O157 : H7 and invA gene in Salmonella enterica was implemented with DNA intercalating probes‐methylene blue. To improve assay efficiency, the optimal concentration of MB was determined to be 30 μM. The real‐time electrochemical LAMP results of gene serial dilutions were compared to the fluorescence‐based detection method. For E. coli O157 and Salmonella, the assay detection limits were 10 DNA copies and 1 DNA copy, respectively, in a reaction time of less than 30 min. The electrochemical and optical LAMP method analyses were realized with 10 % milk to simulate the turbid environment of real food samples. In real‐time LAMP of Salmonella in a turbid environment, the detection limit of 10 copies without pretreatment was possible using the electrochemical method only. Our electrochemical device was used for bacterial detection in 150 turbid food samples, including juice, milk, and soy milk. This electrochemical device has many advantages, including size, portability, high specificity, and high sensitivity, while also being a user‐friendly device that provides stable signals. Thus, to the best of our knowledge, this new electrochemical device demonstrates the best performance for bacterial detection in the rapid contaminated food detection category.

Chip-Based and Wearable Tools for Isothermal Amplification and Electrochemical Analysis of Nucleic Acids

“…A similar strategy was also reported in Reference [62] for the real-time monitoring of the LAMP reaction. In particular, the researchers used methylene blue as a redox probe for the hybridization reaction.…”

Current methods for diagnosis of human coronaviruses: pros and cons

“…1(c)) [59,71]. Previously, the flow visualisation strip was designed in capturing nucleic acids of the MERS-CoV through the LAMP assays [100], in which researchers created the cross primers to target the N gene. The two loops contained the biotin and the fluorescein isothiocyanate as a marker, and after binding with the streptavidin through the gold nanoparticle to form the complex, two loops captured the antibodies.…”

Recent advances in loop-mediated isothermal amplification (LAMP) for rapid and efficient detection of pathogens

“…( DehghanEsmatabadi et al., 2015 ) – ( Wachiralurpan et al., 2018 ) Recent studies have been focused on developing rapid,enhanced and specific detection methods of LAMP assay and several modifications are being made to improve the molecular diagnostic parameters. LAMP technique has been proven to be a versatile and flexible method applied in diagnostic methods of diseases caused by several microorganisms including bacteria ( Huang et al., 2018 ), virus ( Parida et al., 2005 ) and parasites ( Avendaño and Patarroyo, 2020 ).…”