Electrochemical sensing of acetaminophen using multi-walled carbon nanotube and β-cyclodextrin

Acetaminophen is one of the most commonly and widely used painkillers worldwide. Because of its increased use in the past several decades, APAP is now present at higher concentrations in source water, thus necessitating its monitoring. In this work, we report a low-temperature, solution-processed modification of multi-walled carbon nanotubes (MWCNT) with β-cyclodextrin (βCD) on glassy carbon electrode for detecting low levels of acetaminophen in water. This process combines the adsorption properties of βCD with high surface area of carbon nanotubes. An improved dispersion of MWCNT was observed due to the hydrophilicity of βCD. A surface-limited process involving equal number of protons and electrons controlled the electrochemical reaction of acetaminophen with the sensor. The sensor’s limit of detection was 11.5nM and its linear response was from 50nM to 300μM. The sensors exhibited a reproducible and stable response over four weeks and negligible interference from commonly present chemicals in urine, such as dopamine and ascorbic acid. These promising results could facilitate the development of simple and low-cost electrochemical sensors for monitoring of APAP in water.