Carbon nanotube-adsorbed electrospun nanofibrous membranes as coating for electrochemical sensors for sulfhydryl compounds

A new method to modify electrodes with carbon nanotubes (CNT) was developed. Multiwalled carbon nanotubes (MWNT) were adsorbed on the electrospun nylon-6 nanofibrous membranes (Ny-6-NFM) and used as a coating to modify conventional glassy carbon electrodes. The modified electrode was designed for the amperometric detection of sulfhydryl compounds with the potential held at +0.3 V vs. Ag/AgCl. The modified electrode showed a linear response for cysteine up to 0.4 mM (R2=0.997), with a sensitivity of 5.1 µA/mM and a detection limit of 15 µM. Other sulfhydryl compounds showed similar results. After use, the Ny-6-NFM was easily peeled off, leaving the bare electrode surface back to its original electrochemical behaviour. This is the first attempt to use a disposable membrane functionalized with MWNT for electroanalytical purposes.