Peer Reviewed: The Prospects of Clay Mineral Electrodes

Abstract

Because of clay's unique properties, clay mineralchemically modified electrodes (Cm-CMEs) are very suitable for many chemical sensor applications (1-4). A successful chemical sensor must have good sensitivity, selectivity, speed, and longevity. In economic terms, inexpensive, abundant materials and cheap and easy preparation methods certainly make clays attractive. In green chemistry terms, environmentally friendly analytical protocols and devices, negligible waste, and nontoxic materials make clays of considerable interest to the analytical community. The ultimate goal is to properly utilize the high cationexchange capacity (CEC) and intrinsic catalytic properties of clay minerals to construct versatile chemical sensors. This article describes basic preparation and characteristics of Cm-CMEs in several important chemical sensor applications.

Selective covalent immobilization of catechol on activated carbon electrodes

“…Absence of any CAO (ortho-quinone) like structure formation is the possible reason for the failure of any immobilization step with the Re case. In the case of DA, since it exists as cationic form (the terminal amino group as ÀNH þ 3 , pKa = 8.87 [19]) in a neutral solution of pH 7, it may preferentially adsorb to negatively charged surface functional groups through electrostatic attractions, which when transferred to the blank solution gets leached out from the surface. Hence, DA did not show immobilization peak in CV unlike the CA ads in this work.…”

DNA Biosensors Based on Nanostructured Materials

“…Clays can act as ionexchangers, and therefore can serve as useful materials in the preparation of modified electrodes [137]. The ion-exchange properties of different clays incorporated into CPEs were investigated using electrochemical methods [138,139].…”

Electron Transfer of <i>Shewanella oneidensis</i> MR-1 at Clay-Modified ITO Electrode

“…Indeed, the combination of clays with electrodes provides the desired sensitivity, durability, selectivity, and speed of sensors. Moreover, it should be noted that the cost of preparing clay-modified sensors is significantly less than for the preparation of other types of modified sensors [21]. In the case of CMEs, electron transfer occurs through channels by [16] the physical diffusion of mediators within the clay film [22] [23].…”