Reverse transcriptase loop-mediated isothermal amplification assisted with localized surface plasmon resonance of gold nanorods for viability assessment of Lactobacillus acidophilus in yogurt

Abstract

In light of the growing production and consumption of functional foods, it is crucial to develop new methods to assess the authenticity of these products and prevent fraud and mislabeling. In this research, by integrating reverse transcription loop-mediated isothermal amplification (RT-LAMP) and the localized surface plasmon resonance (LSPR) effect of gold nanorods (GNRs), the viability of the probiotic bacteria has been evaluated. The RT-LAMP-GNR method effectively amplifies and identifies bacterial 16S-rRNA within 60 min. The efficiency of the RT-LAMP method was assessed by its implementation using RNA isolated from Lactobacillus acidophilus strain (L. acidophilus) and commercial probiotic yogurts. The method's limit of detection (LoD) was 10⁴ bacterial cells per ml, and its sensitivity was 10⁻⁵ ng/ml RNA.