Optimized detection of Salmonella typhimurium using aptamer lateral flow assay

Area of Science:

• Biotechnology
• Biosensor Development
• Food Safety

Background:

• Salmonella typhimurium is a major cause of foodborne illness, with diagnosis complicated by overlapping symptoms.
• Current diagnostic methods for S. typhimurium lack precision and efficiency, necessitating novel approaches.

Purpose of the Study:

• To develop and optimize a novel aptamer-based lateral flow assay (LFA) biosensor for the rapid and accurate detection of Salmonella typhimurium.
• To utilize the Taguchi optimization method for enhancing the performance of the aptamer LFA.

Main Methods:

• Development of a biosensor using anti-Salmonella aptamers conjugated with gold nanoparticles (GNPs) for lateral flow assay.
• Application of the Taguchi optimization method to determine optimal concentrations of immobilized bacteria and nanobioprobe.
• Evaluation of the assay's detection limit, reaction time, and specificity against other food pathogens.

Main Results:

• Optimal LFA conditions identified at 10^8 CFU/mL immobilized bacteria and 1.5 μg/μL nanobioprobe concentration.
• Visual detection limit for S. typhimurium established at 10^5 CFU/mL.
• Assay provided results within 20 minutes with no significant cross-reactivity with other food pathogens.

Conclusions:

• The aptamer-LFA biosensor, optimized via the Taguchi approach, offers a reliable, simple, and accurate method for S. typhimurium detection.
• This developed method holds potential as a portable diagnostic kit for bacterial identification and detection.