This review describes recent advances in the fabrication of electrochemical (bio)sensors based on screen-printing technology involving carbon materials and their application in biomedical, agri-food and environmental analyses. It will focus on the various strategies employed in the fabrication of screen-printed (bio)sensors, together with their performance characteristics; the application of these devices for the measurement of selected naturally occurring biomolecules, environmental pollutants and toxins will be discussed.

This paper describes the fabrication of a sensor for 1-hydroxypyrene (1-OHP) based on a screen-printed carbon electrode (SPCE) modified with a molecularly imprinted polymer (MIP); 1-OHP was chosen as a model metabolite of polyaromatic hydrocarbons (PAHs). It was shown that 1-OHP could be readily oxidised at a plain SPCE and the electrochemical mechanism was found to involve an ECE (electron transfer–chemical reaction–electron transfer) process. The MIP for 1-OHP was prepared using only divinylbenzene (DVB) and styrene as monomers and the binding was only based on hydrophobic interactions. Batch binding studies revealed that optimum uptake of 1-OHP by the MIP occurred from solutions containing 35% water in methanol. Selectivity of the binding sites in the MIP was examined by performing uptake studies in the same solution containing either phenol or 1-naphthol; the specific binding of 1-OHP was twenty times greater than the former and five times greater than the latter. Preliminary calibration studies were performed with the MIP-SPCE using a two-step approach; accumulation was carried out in 35% water in methanol followed by measurement in 50% methanol–0.025 mol dm⁻³ phosphate buffer pH 12. This two-step non-competitive affinity assay gave encouraging results and indicated potential for use in pollution studies.

Screen‐printed carbon electrodes (SPCEs) bearing a surface‐adsorbed antibody against aflatoxin B₁ (AFB₁) were used in a competitive immunoassay, based on competition of free analyte with a biotinylated aflatoxin B₁ conjugate. Subsequent addition of streptavidin‐alkaline phosphatase (AP) conjugate, followed by a 1‐naphthyl phosphate substrate resulted in the production of the electrochemically active product, 1‐naphthol; this was oxidized using linear sweep voltammetry and constituted the measurement step. Investigations were carried out to test the suitability of reagents by enzyme‐linked immunoassay (ELISA) and to deduce the optimum blocking agent for the immunosensors. Using the electrochemical immunosensor, a calibration plot for AFB₁ was obtained over the concentration range 0.15 to 2.5 ng/mL, giving a detection limit of around 0.15 ng/mL in buffer solution. The immunosensors were fabricated in an array configuration, suitable for use in conjunction with 96‐well microtiter plates; indeed, each step of the immunoassay was performed by dipping the electrodes into microwells. These results represent the initial studies towards the development of an automated instrument for multi‐analyte determinations using immunosensor arrays for mycotoxin detection and form the basis for further studies.