Electrochemical activation of screen-printed carbon strips

Abstract

Screen-printed electrodes, fabricated by thick-film technology, represent an attractive avenue for routine electrochemical sensing. However, the composite character of strips fabricated from commercial carbon strips results in slow rates of heterogeneous electron transfer. The aim of this study was to establish a rapid electrochemical procedure for in situ activation of screen-printed electrodes. Short pre-anodization periods were shown to increase the electrochemical activity for a wide range of irreversible and quasi-reversible redox processes. Activation parameters influencing the enhanced reversibility at strips fabricated from two common carbon inks were explored. The effect of the ink-curing temperature on the redox activity was also examined. Cyclic and differential-pulse voltammetry, X-ray photoelectron spectroscopy and scanning electron microscopy were used for monitoring changes in the electrochemical reversibility, surface area and morphology and the introduction of oxygen surface functionalities. The sensing utility of activated carbon strip electrodes is demonstrated for several analytes, and future prospects are discussed. The simple, yet effective, electrochemical pretreatment is compatible with on-site application of disposable electrodes.