Electrochemical Sensors Modified with Nanofibrous Membranes

2 Electrochemical Sensors Modified with Nanofibrous Membranes 

Electrochemical sensors, modified with nanomaterial, have contributed to create great expectations in the last decade [4-8]. New materials such as carbon nanotubes [8-10], metal [3, 5, 11-16] and polymer nanoparticles [14, 17-20], carbon nanofibers [21-23], and boron-doped diamond nanograss [24] are ideal for electrochemical sensors due to their high surface area, high aspect ratio, and enhanced catalytic properties [25-30]. 

Regardless to the material used, electrochemical sensors suffer from several drawbacks, one of the most known is the passivation of its surface [31]. The oxidation of electroactive substances involves the formation of oxidized material at the electrode surface which blocks further reaction at the electrode [32]. For instance, during the electrochemical detection of biological analytes in matrices with a high content of phenolic compounds, the surface of the electrode is contaminated and the subsequent analysis is compromised [33]. 

Electrospun nanofibrous membranes can offer potential solutions to overcome the drawback. Electrodes coated with nanofibrous membranes can minimize or cancel passivation phenomena. As it will be shown later, such electrodes can be used for prolonged time in solution containing potential interfering substances without suffering from the problem of passivation. This is one of the potential applications described in the next section. 

Furthermore, nanofibrous membranes can be used to develop flexible and conductive nanofibrous electrodes, either with their modification with conducting polymers, or with the inclusion of activated multiwalled carbon nanotubes. The resulting membranes, made conductive by the incorporation of carbon nanotubes or conductive polymers, can be modeled in different forms, as desired, such as cylinders, balloons, spirals, and so on. 

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To focus on the topic, in the next sections, the general term nanoelectrochemistry will be whittled down to the study of conductive surfaces coated with material having one or more external dimensions in the nanoscale and the apphcations will be limited to electrochemical sensors and biosensors modified with nonwoven nanofibrous membranes prepared by electrospinning. 

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