Selection of DNA aptamers for sensing drugs treating eye disease: atropine and timolol maleate

Using capture-SELEX, DNA aptamers for two important ocular drugs were obtained, allowing highly sensitive detection of low volume samples. Effective monitoring of ocular drugs is crucial for personalized medicine and improving drug delivery efficacy. However, traditional methods face difficulties in detecting low drug concentrations in small volumes of ocular fluid, such as that found on the ocular surface. In this study, we used capture-SELEX to select aptamers for two commonly used ocular drugs, timolol maleate and atropine. We identified TMJ-1 and AT-1 aptamers with binding affinities of 3.4 μM timolol maleate and 10 μM atropine, respectively. Our label-free TMJ-1 biosensor using thioflavin T staining achieved a limit of detection (LOD) of 0.3 μM for timolol maleate. The AT-1 biosensor showed an LOD of 1 μM for atropine, and exhibited a 10-fold higher sensitivity compared to UV-visible spectroscopy. Future research in this area holds promise in enhancing drug delivery monitoring and improving the treatment of ocular diseases.