This study reports a simple and rapid aptamer-based sensor platform designed for the sensitive and selective detection of human non-small cell lung cancer (NSCLC) cells. Under standard conditions, gold nanoparticles (AuNPs) remain dispersed and exhibit a characteristic peak at 520 nm. However, the addition of sodium chloride (NaCl) destabilizes the charge of the solution, leading to the aggregation of AuNPs. The AS1411 aptamer can adsorb onto the surface of AuNPs, effectively preventing their aggregation. In the presence of A549 cells, the AS1411 aptamer is induced to form stable G-tetrads, which allows for specific binding to the cells and results in the aggregation of AuNPs in the NaCl solution. This proposed aptasensor platform demonstrates high specificity for A549 cells when compared to other control human normal cells. The method exhibits a dynamic range of 101 to 106 cells per mL, with a detection limit of 7 cells per mL.