A label-free liquid crystal-assisted aptasensor for trace level detection of tobramycin in milk and chicken egg samples.

Developed herein is an aptasensing array based on liquid crystal (LC) for monitoring of tobramycin (TOB) antibiotic. The direction of LC molecules from vertical to a random status was induced by the conformational changes of the specific aptamer due to its selective interaction with the target. The dark view of the aptasensing platform changed to colorful through observation by a polarized light microscope that clarifies the TOB presence. The aptasensor is especially able to determine TOB in the linear concentration range of 0.005-600 pM with a limit of detection (LOD) as 0.0021 pM. The TOB values can be determined successfully in the milk and chicken egg samples that highlights the potential applicability of the designed aptasensor. The proposed sensing approach is facile, operator-independent, label-free, and ultra-sensitive, making it novel for developing real-time portable sensing devices for future.