Neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein are pathological characteristics of Alzheimer’s Disease (AD). Thus, the use of biosensors that bind to NFTs are beneficial for in vivo detection of tauopathy. This study evaluates the use of Lansoprazole (LSZ) as an indicator of NFTs in AD brains. 19F MRS of AD and control brains with LSZ was acquired using a 3.0T clinical MRI scanner. We demonstrate that the 19F signal from LSZ interacts with NFTs in a rat model of AD. This shows potential in using LSZ to distinguish between AD and healthy brains with a clinical 3.0T scanner.