Multiple sclerosis affects 2.8 million people worldwide, with diagnosis often delayed due to the high costs of MRI scans and invasive procedures. MicroRNA-145-5p has emerged as a promising MS biomarker, showing 79% sensitivity and 87% specificity in distinguishing patients from healthy controls. However, current detection methods require costly qRT-PCR equipment and trained personnel. We propose a plasmid-based fluorescent biosensor using engineered E. coli to detect miR-145 at point-of-care. Our design employs a toehold switch — an RNA hairpin complementary to miR-145 that blocks the ribosome binding site, preventing GFP translation. Upon miR-145 binding, the hairpin unfolds and activates GFP expression, producing measurable green fluorescence. If validated, this affordable biosensor could enable MS screening in resource-limited settings where MRI is unavailable, significantly improving diagnosis in underserved populations.