Electropolymerization of β-cyclodextrin onto multi-walled carbon nanotube composite films for enhanced selective detection of uric acid

Abstract

An amperometric uric acid (UA) sensor incorporating a multi-walled carbon nanotubes (MWCNT) network in Nafion and electropolymerized -cyclodextrin (-CD) layer is investigated. The electrochemical sensor is comprised of a glassy carbon electrode modified with Nafion-MWCNT nanocomposite film, a -CD polymer inner selective layer, and a Hydrothane polyurethane (HPU) outer selective coating. The surface morphology and electronic structure of the electrode material are characterized using transmission electron microscopy (TEM), scanning electron microscope (SEM), and Fourier transform infrared (FTIR) spectroscopy. The electrocatalytic activity of the sensor is studied using cyclic voltammetry (CV), chronocoulometry (CC) and differential pulse voltammetry (DPV). Analytical performance of the electrochemical sensor scheme with and without MWCNT and/or -CD polymer is determined from direct UA injection during an amperometric analysis. The effective surface area is notably higher for Nafion-MWCNT coated glassy carbon electrodes, which in turn enhanced the sensitivity when coated with -CD polymer. The results indicated an excellent electrocatalytic property of Nafion-MWCNT/-CD film for UA detection with enhanced sensitivity (2.11 A•mM-1), wide linear responses over physiologically relevant concentrations, and fast response times. Enhancement is attributed to MWCNT offering increased electroactive surface area and the ability of -CD to selectively sequester UA.

New Generation of Electrochemical Sensors Based on Multi-Walled Carbon Nanotubes

“…Using DPV and the developed sensor (HIV-p24/CTS/MWCNT/GCE), a low limit of detection (0.083 pg cm −3 ), good selectivity, repeatability, reproducibility, stability, and accuracy were reached for the proposed electroanalysis; validation was performed by comparative studies with enzyme-linked immunosorbent assay (ELISA). The outstanding ability of MWCNT-based electrochemical sensors to simulate redox reactions that occur in vivo has also been demonstrated with the electroanalysis of hemoglobin [43], amino acids [44], cholesterol [45], bilirubin [46], neurotransmitters, and related compounds [47][48][49], and even microorganisms [50], in mammalian fluid samples, achieving great results and contributing to the early diagnosis and treatment of several related diseases.…”

Sensors Based on Molecularly Imprinted Polymers

“…Similarly to pyrrole, cyclodextrins can be polymerized by an electrochemical way giving the opportunity to control the process by adjusting of parameters like voltage range, rate of voltage change, number of cycles etc. Layer of cyclodextrins overs an electrode is easily producible in an electrochemical process [68][69][70][71][72][73]. Overview of the aforementioned materials is given in table 1.…”

Flexible Nanoporous Gold Electrodes for Electroanalysis in Complex Matrices

“…Uric acid is an important biomarker and abnormal levels have been implicated in various diseases and metabolic disorders. [36][37] Thus, there has been a strong interest in the measurement of uric acid using both enzymatic [36][37] and nonenzymatic electrochemical methods [37][38] with rigid [39][40][41][42][43][44] as well as flexible electrodes. [45][46][47] In the present work, because the substrate is bendable and the active material has biofouling resistant properties, these electrodes could have promising applications in electrochemical sensing in complex media in nontraditional locations.…”