We demonstrate rapid, sensitive and label-free detection of whole-cell E. coli utilizing interferometric reflectance imaging enhancement technique, with a limit of detection of 2.2 CFU/ml from a buffer solution with no sample preparation. Our sensor platform provides visualizing and counting individual pathogens captured on the large sensor surface, as well as morphological characterization of the captured particles by high optical magnification imaging modality for validating the recorded detection events as the target bacteria. In addition, we show that our biosensor's detection capability is unaffected by the sample complexity by testing its performance in tap water. Also, the specificity of our biosensor is validated by comparing its response to target bacteria E. coli and non-target bacteria S. aureus, K. pneumonia and P. aeruginosa. Therefore, our sensitive and label-free detection method offers new perspectives for direct bacterial detection in real matrices and clinical sample.