The current research leverages a nanotechnology enabled sensor platform for highly sensitive detection of pharmaceuticals contaminants in water samples using electrochemical impedance spectroscopy. The sensor surface consists of lithographically patterned gold electrodes and is functionalized with anti-pharmaceutical antibodies. A nanoporous alumina membrane is placed over the sensor surface to achieve enhanced signal amplification. Erythromycin and Ibuprofen were successfully detected on the sensor in amounts as low as parts per quadrillion. The design has potential to be developed into portable diagnostic equipment, offering rapid, inexpensive and highly reliable detection of pharmaceuticals with applications in the assessment of water quality.