Electrochemical Biosensing Systems Based on Carbon Nanotubes and Carbon Nanofibers

Abstract

Carbon nanomaterials are in the forefront of research in a variety of chemical and physical disciplines. Of these, certain nanostructures seem to be suitable for the development of electrochemical biosensors. In particular carbon nanotubes, and carbon nanofibers have specific chemical and physical characteristics that lent them ideal for the development of biosensors with unique analytical characteristics. In particular, their conductivity, surface area, inherent and induced chemical functionalities, and biocompatibility provide the grounds for the development of a new era of electrochemical biosensors. In this review, we will examine the recent developments of biosensor design based on these new nanostructures.

Functionalized carbon nanotubes and nanofibers for biosensing applications

“…They have lengths of the order of µm, while their diameter varies between some tens of nm to several hundred nm. Due to their specific properties, CNFs have also been used for biosensor development [13].…”

Nanohybrid Materials as Transducer Surfaces for Electrochemical Sensing Applications

“…So, in both hybrid system, whether had carbon nanotubes or carbon nanofibers, the results indicate that the best compromise between sensitivity and reproducibility was achieved for a 0.1 mM AuCl 4 À electrodeposited at À5 mA during 60 seconds. In Figure 5 SEM images of the hybrid electrodic surfaces were shown.…”

“…These results were also observed for the other gold concentrations in study (data not show). In order to achieve the best relation between sensitivity and reproducibility the concentration of 0.1 mM of AuCl 4 À was selected (Figure 4). For the hybrid transducer surface between CNFs and NPAus was verified a similar behavior (data not show), therefore the selected values for the studied parameters were the same.…”

“…Gold nanoparticles have been formed from AuCl 4 À of different concentrations prepared in 0.1 M HCl by applying a constant current intensity for a period of time. Three gold concentrations (0.1 mM AuCl 4 À , 0.5 mM AuCl 4 À , 1 mM AuCl 4 À ), 3 current intensities (À5 mA, À10 mA, À100 mA) and 3 deposition times (60 s, 120 s and 300 s) were studied using the procedure described in Section 2.3.2. Figure 3 shows the results obtained for the gold concentration of 1 mM with the transducer previously modified with MWCNTs.…”

“…Carbon nanotubes (CNTs) and carbon nanofibers (CNFs) based electrochemical biosensors have been used in the development of new designs of electrochemical biosensors which have found widespread use in several analytical applications [3][4][5][6][7][8][9][10]. Most applications of these materials rely on the modification of the working electrodes [8].…”