Layer-by-Layer Assembly of Electroactive Dye/LDHs Nanoplatelet Matrix Film for Advanced Dual Electro-optical Sensing Applications

Abstract

It proved that the most destructive effects of the toxic Al3+ ion on the human nervous system and disease that are involved with this system, such as Alzheimer's. The development of solid-state electrodes is still in its infancy during the sensor-based detection methods for Al3+. Hence, in this study, a novel flexible ITO/PET-based electrochemical solid-state sensor was designed and constructed. Modification of the surface of electrode bedding was done by layer-by-layer (LbL) assembly of Mg–Al LDH. nanoplatelets along with alizarin red S (ARS) in an interconnected matrix film. In the molecular design of sensing base of the electrode, the electroactive organic units (ARS molecules) present in the ITO/PET-layered (ARS/LDHs)n matrix are involved in electrochemical reactions when exposed to the target molecule (Al3+ ion), so the electrochemical changes of the new formed Al-chelated system are detectable. This type of sensor is used for sensitive and selective detection of Al3+. The minimum sheet resistance, morphology and high electrocatalytic activity of the modified matrix film are obtained in the fifth cycle of LbL assembly technique. In this electrochemical sensor, both electrochemical and optical methods were detected with high sensitivity and selectivity of Al3+, so that in a cyclic voltammetry electrochemical method, the lower detection limit of 10.1 nM with a linear range of [0.2–120 μM] was obtained compared to the fluorescence-based optical method.

Recent Advances in Layered Double Hydroxide-Based Electrochemical and Optical Sensors

“…Dyes are frequently doped into LDHs for optical detection, but the redox reactions of various dyes produce electrochemical signals. Lajevardi Esfahani et al fabricated a simultaneous electrochemical and optical Al 3+ sensor via a layer-by-layer assembly of MgAl-LDHs and alizarin red S (ARS) on an ITO/PET substrate [57]. A five-layer electrode exhibited the lowest sheet resistance, with successive layers decreasing the conductivity and ion diffusion.…”

“…Rare earth materials-based double hydroxides are efficient materials for the fluorescent detection of the Fe(III) ion [54][55][56]. Layer-by-layer deposition of LDHs and dye molecules enhances the interaction between catalyst and the active molecules that enhance both electrochemical and optical sensing ability [57].…”

Recent Progress of Layer‐by‐layer Assembly, Free‐Standing Film and Hydrogel Based on Polyelectrolytes

“…[ 45 ] A modification of the electrochemical sensor with the inclusion of an electroactive dye molecule is also proposed. [ 46 ]…”

A novel ratiometric sensor for fluorimetric and visual dual-mode detection of Al3+ in environmental water based on the target-regulated formation of Eu MOFs

“…Commonly employed analytical techniques for Al 3+ detection include high-performance liquid chromatography, 5 mass spectrometry, 6 electrochemical analysis 7 and graphite furnace atomic absorption spectrometry. 8 However, these methods often need high-cost instruments, complicated operations, time-consuming detection processes and skilled technicians.…”