Early detection of bacteria in water treatment is desired to mitigate system biofouling and potential human health impacts. This research involved the development of an antibody-based sensor, which was attached to a hydroxypropyl cellulose (HPC) modified cellulose acetate ultrafiltration membrane surface, to target bacteria. HPC was chosen because it collapses above and expands below a lower critical solution temperature (43 degrees C), thus allowing temperature modulation. The membrane had a high target recovery efficiency (10-18%) in both single bacterium and complex samples (simulated by adding organics and competitive organisms). Sensor recovery was decreased (to 5-7%) following temperature activation (above 50 degrees C) due to adverse impacts of temperature on the antibody. The membrane was able to be regenerated (with 0.1 M NaOH) and reused three consecutive times. The thermally responsive sensing membrane developed from this work was specifically developed to detect biofoulants in membrane-based water treatment processes. However, it could be adapted to address a range of environmental detection concerns, such as pathogen detection. Published by Elsevier B.V.