A New Sensor for Methyl Paraben Using an Electrode Made of a Cellulose Nanocrystal–Reduced Graphene Oxide Nanocomposite

Abstract

A new cellulose nanocrystal–reduced graphene oxide (CNC–rGO) nanocomposite was successfully used for mediatorless electrochemical sensing of methyl paraben (MP). Fourier-transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM) studies confirmed the formation of the CNC–rGO nanocomposite. Cyclic voltammetry (CV) studies of the nanocomposite showed quasi-reversible redox behavior. Differential pulse voltammetry (DPV) was employed for the sensor optimization. Under optimized conditions, the sensor demonstrated a linear calibration curve in the range of 2 × 10−4–9 × 10−4 M with a limit of detection (LOD) of 1 × 10−4 M. The MP sensor showed good reproducibility with a relative standard deviation (RSD) of about 8.20%. The sensor also exhibited good stability and repeatability toward MP determinations. Analysis of MP in cream samples showed recovery percentages between 83% and 106%. Advantages of this sensor are the possibility for the determination of higher concentrations of MP when compared with most other reported sensors for MP. The CNC–rGO nanocomposite-based sensor also depicted good reproducibility and reusability compared to the rGO-based sensor. Furthermore, the CNC–rGO nanocomposite sensor showed good selectivity toward MP with little interference from easily oxidizable species such as ascorbic acid.

Zinc Oxide Nanoparticles as Antifouling Materials for the Electrochemical Detection of Methylparaben

“…The proposed reaction for the electrochemical oxidation of MePa begins with a one‐step single electron and proton transfer step, which is chemically irreversible. The electron transfer occurs to produce a radical quinone species (see inset to Figure 1b) [15] . The radical is typically unstable and is involved in further chemical transformations to give the reaction products that are responsible for electrode fouling.…”

“…Among others, modified electrodes are considered as ideal candidates for the development of electrochemical sensor surfaces for the detection of phenolic functional group containing analytes, which are notoriously associated with electrode fouling on unmodified electrodes [12] . The performance of modified electrodes depends on many factors including the electron transfer capability between the electrode material and analyte, the electrochemically active surface area, the number of exposed active sites and their stability in the reaction media [5,13–15] . The development of several nanostructures with unique combinations and morphologies has opened up new avenues for nanomaterial‐based sensors.…”

“…[12] The performance of modified electrodes depends on many factors including the electron transfer capability between the electrode material and analyte, the electrochemically active surface area, the number of exposed active sites and their stability in the reaction media. [5,[13][14][15] The development of several nanostructures with unique combinations and morphologies has opened up new avenues for nanomaterial-based sensors. Recent reports clearly suggest the plausible detection of parabens by using graphene oxide (GrO), [15] carbon nanofibers (CNFs), [16] multi-walled carbon nanotubes (MWCNTs) [5] and their combination with noble metals.…”

“…[5,[13][14][15] The development of several nanostructures with unique combinations and morphologies has opened up new avenues for nanomaterial-based sensors. Recent reports clearly suggest the plausible detection of parabens by using graphene oxide (GrO), [15] carbon nanofibers (CNFs), [16] multi-walled carbon nanotubes (MWCNTs) [5] and their combination with noble metals. However, the deposition of these materials onto the sensing electrodes requires either a multi-stepped approach or high-cost noble metals, yielding materials with the ideal properties that prevent fouling.…”

Cellulose Nanocrystals/Graphene Hybrids—A Promising New Class of Materials for Advanced Applications

“…Several approaches used to produce some unmodified CNC/RGO hybrids have been reported for which the common method used to produce CNC/GO can be applied. Wan Khalid prepared COC/RGO nanocomposite by dispersion/ultrasonication of 1 mg RGO in ethanol and 1 mg of CNC in deionized water [175]. The supernatant was eliminated by centrifugation to recover the final hybrid.…”