Multi-walled carbon nanotube/ polypyrrol nanocomposite modified glassy carbon electrode as a new sensor for determination of Buprenorphine

Buprenorphine (BN, Scheme 1) is a strong semi-synthetic opiate painkiller with as sovereignty of 20–40 times higher than that of morphine [1,2]. Several methods havebeen reported for the determination of BN. Among these methods, electrochemical methods show some advantages such as extreme simplicity, high sensitivity, easyand low-cost [3]. The present work reports preparation and characterization of a new potentiometric sensor for determination of BN based on doped polypyrrole films. Aglassy carbon electrode was coated with a thin layer of multi-walled carbon nanotubes (MWCNTs) and subsequently electro-polymerized with polypyrrole. The prepared electrode was used for the voltammetric determination of buprenorphine. Surface morphology and electrochemical properties of the fabricated composite electrode were examined by atomic force microscopy and cyclic voltammetry (CV). The effect of several experimental variables, such as pH of the supporting electrolyte, drop size of the cast MWCNTs suspension and number of electropolymerization cycles were optimized by monitoring the CV responses of the modified electrode toward BN. The modified electrode is applicable to determine BN in the linear range of 0.06-40 μM with a detection limit 28 nM. The sensor was used for recovery of analytes in urine samples.