A system (10, 100, 300, 400) is provided for identifying certain targeted cells or tissues in a body. The system (10, 100, 300, 400) preferably includes at least one ingestible capsule that accommodates or supports (20) at least one of an illuminating module (30, 114, 322, 422, 452), a detecting module (40, 124, 324, 424, 434, 454), an imaging module (50, 326, 432, 456), a control module (60), or a reservoir (70, 132, 312, 412, 442) suitable for retaining and releasing one or more nanoshells. A method (200) is also provided for employing the system (10, 100, 300, 400) to detect, image or otherwise interact with diseased or abnormal cells and/or tissues in a body. The system (10, 100, 300, 400) and method (200) provided allow for improved diagnosing, treating and imaging techniques and for increased sensitivity and specificity in efficiently distinguishing targeted diseased or abnormal cells or tissue from surrounding healthy cells or tissue.