(searched for: doi:10.1016/b978-0-12-409547-2.13482-1)
Nanomaterials, Volume 12; https://doi.org/10.3390/nano12234171
Micro and nano interdigitated electrode array (µ/n-IDEA) configurations are prominent working electrodes in the fabrication of electrochemical sensors/biosensors, as their design benefits sensor achievement. This paper reviews µ/n-IDEA as working electrodes in four-electrode electrochemical sensors in terms of two-dimensional (2D) planar IDEA and three-dimensional (3D) IDEA configurations using carbon or metal as the starting materials. In this regard, the enhancement of IDEAs-based biosensors focuses on controlling the width and gap measurements between the adjacent fingers and increases the IDEA’s height. Several distinctive methods used to expand the surface area of 3D IDEAs, such as a unique 3D IDEA design, integration of mesh, microchannel, vertically aligned carbon nanotubes (VACNT), and nanoparticles, are demonstrated and discussed. More notably, the conventional four-electrode system, consisting of reference and counter electrodes will be compared to the highly novel two-electrode system that adopts IDEA’s shape. Compared to the 2D planar IDEA, the expansion of the surface area in 3D IDEAs demonstrated significant changes in the performance of electrochemical sensors. Furthermore, the challenges faced by current IDEAs-based electrochemical biosensors and their potential solutions for future directions are presented herein.
Polymers, Volume 14; https://doi.org/10.3390/polym14194150
Two metal oxide nanoparticles, magnesium oxide nanoparticles (MgONPs) and aluminum oxide nanoparticles (Al2O3NPs), were synthesized from green sources, Salvia officials and Cuminum cyminum seed extract, respectively. These nanoparticles were used for construction of potentiometric enhancement sensors employed for the estimation of ranitidine hydrochloride (RNT) in authentic powder and commercial products. The electroactive substance ranitidine-phosphotungstate (RNT-PT) was formed by combining RNT with phosphotungstic acid (PTA) in the presence of plasticizing material o-nitrophenyloctyl ether (o-NPOE). The outcomes showed that the enhanced MgO and Al2O3 nanosensors behaved linearly across the concentration ranges 1.0 × 10−9–1.0 × 10−2 and 1.0 × 10−10–1.0 × 10−2 mol L−1, respectively. However, the conventional sensor (RNT-PT) displayed a linearity over 1.0 × 10−6–1.0 × 10−2 mol L−1. Least square equations were calculated as EmV = (54.1 ± 0.5) log (RNT) + 762.33, EmV = (58.6 ± 0.2) log (RNT) + 696.48, and EmV = (52.2 ± 0.7) log (RNT) + 756.76 for enriched nanometal oxides modified and conventional sensors, respectively. The correlation coefficients of regression equations were 0.9997, 0.9995, and 0.9992 for the above suggested sensors, respectively. The recorded results showed excellent sensitivity and selectivity of the modified nanometal oxide sensors for the quantification of the analyzed drug in its authentic samples and commercial products.