Selective detection of albuterol in the presence of uric acid using a glassy carbon electrode modified with multi-walled carbon nanotubes and poly(pivalic acid)

A selective detection of albuterol has been carried out in pharmaceuticals for its therapeutic use and urine samples for doping control purposes using a glassy carbon electrode (GCE) modified with multi-walled carbon nanotubes (MWCNT) and poly(pivalic acid) (PPA). The modified electrode (PPA/MWCNT/GCE) was applied for the detection of albuterol in the presence of uric acid (UA) since the urine samples contain excess amount of UA. The PPA/MWCNT/GCE showed a high electrocatalytic effect towards the oxidation of both albuterol and UA. Compared with a bare GCE and MWCNT/GCE, the PPA/MWCNT/GCE exhibits a distinct shift of the oxidation potential of albuterol and UA in the cathodic direction and a marked enhancement of the current response and also provides larger peak to peak separation between albuterol and UA for their easier simultaneous determination. The PPA/MWCNT/GCE was used for the determination of albuterol using square wave voltammetry in 0.1 M phosphate buffer solution (PBS) at pH 8.0. The peak current increased linearly with the concentration of albuterol in the range of 5.0 × 10−8–7.0 × 10−5 M with a detection limit of 1.2 × 10−8 M. The selective determination of albuterol makes the developed method of great interest for doping control purposes and monitoring its therapeutic use.