A B S T R A C TThis review addresses recent advances in the development of screen-printed electrode based biosensors modified with different nanomaterials such as carbon nanotubes, graphene, metallic nanoparticles as gold, silver and magnetic nanoparticles, and mediator nanoparticles (Prussian Blue, Cobalt Phthalocyanine, etc.), coupled with biological recognition elements such as enzymes, antibodies, DNA and aptamers to obtain probes with improved analytical features. Examples of clinical applications are illustrated, together with examples of paper-based electrochemical devices, of multiple detections using arrays of screen printed electrodes, and of the most recent developments in the field of wearable biosensors. Also the use of smartphones as final detectors is briefly depicted.

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Salmonella has represented the most common and primary cause of food poisoning in many countries for at least over 100 years. Its detection is still primarily based on traditional microbiological culture methods which are labor-intensive, extremely time consuming, and not suitable for testing a large number of samples. Accordingly, great efforts to develop rapid, sensitive and specific methods, easy to use, and suitable for multi-sample analysis, have been made and continue. Biosensor-based technology has all the potentialities to meet these requirements. In this paper, we review the features of the electrochemical immunosensors, genosensors, aptasensors and phagosensors developed in the last five years for Salmonella detection, focusing on the critical aspects of their application in food analysis.

In the present work, an indirect competitive electrochemical enzyme linked immunosorbent assay (ELISA) has been used for determination of aflatoxin B 1 (AFB 1 ) in barley. The method involves the use of disposable screen-printed carbon electrodes (SPCEs) and anti-aflatoxin B 1 monoclonal antibodies (MAb) for immunosensor development.The specificity of the assay was assessed by studying the cross-reactivity of the MAb relative to AFB 1 . The results indicated that the MAb could readily distinguish AFB 1 from other toxins, with the exception of AFG 1 .The stability of the coating reagents was evaluated using SPCEs coated with AFB 1 -bovine serum albumin (BSA) conjugate. The results showed that the coated electrodes could be used for up to one month after their preparation and storage at 48C.Prior to evaluating the performance of the electrochemical immunosensor for AFB 1 with spiked samples, the effect of barley extract on assay performance was tested. Using this calibration method, the limit of detection (LOD) was found to be 90 pg mL 21 .

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a b s t r a c tScreen-printed glucose, ethanol and fructose biosensors, coupled with portable instrumentation, and their application to monitor micro-alcoholic fermentations (micro-ALFs) in red wine is described. For the fabrication of glucose and ethanol biosensors, graphite screen-printed sensors modified with Prussian Blue were coupled with oxidase enzymes while for the fructose biosensor, a bare screen-printed sensor was coated with fructose dehydrogenase and phenazine methansulphate was used as electrochemical mediator. The working range, reproducibility of probe fabrication and biosensor stability were all evaluated. After a recovery study, performed analysing fortified must-wine samples, the biosensors were employed to monitor micro-ALFs induced by the inoculation of two different strains of Saccharomyces cerevisiae. During the red micro-ALFs, samples of must-wine were collected and analysed by use of both biosensors and spectrophotometric kits. The data obtained demonstrated that a biosensor-based system could represent a useful tool to assist winemakers during wine production.

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