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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.

(Bio)fouling processes arising from nonspecific adsorption of biological materials (mainly proteins but also cells and oligonucleotides), reaction products of neurotransmitters oxidation, and precipitation/polymerization of phenolic compounds, have detrimental effects on reliable electrochemical (bio)sensing of relevant analytes and markers either directly or after prolonged incubation in rich-proteins samples or at extreme pH values. Therefore, the design of antifouling (bio)sensing interfaces capable to minimize these undesired processes is a substantial outstanding challenge in electrochemical biosensing. For this purpose, efficient antifouling strategies involving the use of carbon materials, metallic nanoparticles, catalytic redox couples, nanoporous electrodes, electrochemical activation, and (bio)materials have been proposed so far. In this article, biomaterial-based strategies involving polymers, hydrogels, peptides, and thiolated self-assembled monolayers are reviewed and critically discussed. The reported strategies have been shown to be successful to overcome (bio)fouling in a diverse range of relevant practical applications. We highlight recent examples for the reliable sensing of particularly fouling analytes and direct/continuous operation in complex biofluids or harsh environments. Opportunities, unmet challenges, and future prospects in this field are also pointed out.

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