The electrochemical detection of several pharmaceuticals and personal care products (PPCPs) in water was performed using titanium dioxide nanotube-based (Ti-NT) arrays. Sensing was performed with various pharmaceuticals in water from natural sources, achieving ppb detection limits. Low bias voltages (-1.2 V to +1.2 V) were selected for operation and correlates to sensor performance. Bias voltage was determined by cyclic voltammetry in order to record maximum oxidation and reduction peaks for the specific metal and chemical of interest. The Ti-NT arrays were decorated with various metal nanoparticles to increase the specificity and sensitivity of the sensor. Metals were chosen based on Density Functional Theory methods to calculate which metals are most likely to bind with the chemical of interest. For example, Ti-NTs functionalized with zinc nanoparticles were able to detect ppb levels of ibuprofen, while no detection occurred with the blank Ti-NTs.