Airport security screening is largely concentrated at fixed checkpoints, leaving limited opportunities for continuous monitoring within terminal areas. This paper presents the design and preliminary validation of a ROS2-based autonomous mobile robot intended to provide an additional security layer through real-time object detection, tracking, mapping, navigation, and future integration of non-ionizing terahertz-(THz) imaging. The prototype integrates an NVIDIA Jetson Orin, Intel RealSense D415 camera, RPLidar-A1, Arduino-based motor control, and a mobile platform. ROS2, RViz2, Navigation2, and YOLOv11 were used to combine perception, visualization, motion control, and system monitoring. Laboratory tests demonstrated live indoor mapping, detection of people and objects, persistent tracking identities, target tracking, motor operation, and wireless access. A survey of 54 respondents examined passenger acceptability; half expressed comfort with mobile robotic scanning, while 75.9% believed it could improve airport security. Acceptance depended strongly on non-ionizing operation, privacy protection, transparency, and human oversight. Because the THz camera was not experimentally integrated owing to budget constraints, concealed-object detection remains a proposed capability. The study establishes a functional foundation for future THz-RGB-D-LiDAR fusion, quantitative performance evaluation, cybersecurity assessment, and controlled airport trials. It also identifies key technical, ethical, regulatory, and human-factor requirements for responsible deployment in crowded, safety-critical airport terminal environments.