Electrochemical solid-state nanosensor based on a dual amplification strategy for sensitive detection of (FeIII-dopamine)

Sepehr Lajevardi Esfahani

article info

Article history
Received 30 October 2018
Received in revised form
8 January 2019
Accepted 10 January 2019
Available online 11 January 2019

Keywords: Dopamine, Layer-by-layer (LbL) assembly Solid-state, Electro-active naphthalimide, LDH

abstract

Over the past decades, according to empirical studies, it has been determined that dopamine metabolism plays a key role in many neuropsychiatric diseases. The development of dual-response electrochemical sensors is still in its infancy during the sensor-based detection methods for dopamine. Hence, a novel electrochemical sensor with dual amplification strategy was designed and constructed. In the molecular design of the solid-state structure, a flexible ITO/PET was used. Several nanometric layers of graphene oxide (GO) were deposited on the surface of the ITO/PET using the electrophoretic deposition (EPD) method. Then, during the layer-by-layer (LbL) assembly, the synthesized electro-active naphthalimide dye/LDH nanoplatelets matrix (NALD-n) was displayed in successive layers. The minimum sheet resis- tance, uniform morphology, and high electrocatalytic activity of the modified matrix film were obtained in the fifth cycle of the LbL assembled (NALD-5) modified electrode. This molecular design resulted in a significant increase in the fluorescence emission of electro-active dye in the sensor’s bed containing LDH nanoplatelets and eliminating the effect of GO quenching. This solid sensor was used to detect dual Fe3þ/ dopamine through an electro-active naphthalimide probe on the surface. In this sensor, in terms of electrochemical/optical changes of solid-state, the (OFF/ON/OFF) system was created so that the fluo- rescence emission decreased with the presence of dopamine molecules. The cyclic voltammetric changes of the sensor were well tolerated at a linear range of [1.0 1010-1.5 108 M] for the selective sensing of dopamine with a detection limit (LOD) of 0.06 nM. © 2019 Elsevier Ltd. All rights reserved.