Electrochemical sensor based on palladium-reduced graphene oxide modified with gold nanoparticles for simultaneous determination of acetaminophen and 4-aminophenol

Highlights

• A electrochemical sensor with Au/Pd/rGO was proposed.

• Au nanoparticles deposited on the surface of Pd/rGO/GEC can promote electron transfer.

• The proposed sensor has good sensitivity, stability and selectivity.

Abstract

Herein, a newly developed electrochemical sensor base on the nanohybrid of palladium-reduced graphene oxide modified with gold nanoparticles (Au/Pd/rGO) was established, which was prepared by electrodeposing Au nanoparticles on Pd/rGO modified on a glass carbon electrode. The morphologies and microstructures of the as-prepared nanohybrid were characterized by X-ray photoelectron spectroscopy, Scanning electron microscopy and Infrared spectroscopy. And, experiment results showed that the prepared Au/Pd/rGO nanohybrid exhibited excellent electrocatalytic- activity toward the redox of acetaminophen (PA) and 4-aminophenol (4-AP) simultaneously. The linear detection ranges were 1.00–250.00 μM for PA and 1.00–300.00 μM for 4-AP, with the detection limits of 0.30 μM for PA and 0.12 μM for 4-AP, respectively. Because of the excellent performance of lower detection, wider linear range and better selectivity, the prepared Au/Pd/rGO nanohybrid with more potential applications was a promising candidate for advanced electrode material in electrochemical sensing field.

Introduction

As an analgesic and antipyretic drug, paracetamol (PA) (N-acetyl-p-aminophenol or acetaminophen) is mainly used for the reduction of fever and relief the moderate pain associated with headache, arthritis, postoperative pain, and backache. However, the accumulation of toxic metabolites of the excess of acetaminophen may cause severe and sometimes fatal hepatoxicity, inflammation of the pancreas and skin rashes [1], [2], [3], [4]. 4-Aminophenol (4-AP) is the primary hydrolytic degradation product of paracetamol. [5] As a synthetic intermediate or degradation product of paracetamol, 4-AP has significant nephrotoxicity and teratogenic effect [6], [7]. On account of its high toxicity, the maximum content of 4-AP in pharmaceuticals is limited to 50 ppm (0.005%, w/w) by the United States [8], European [9] and Chinese pharmacopeias. Therefore, it is essential to develop simple, sensitive and accurate analytical methods for the detection of 4-AP and PA. Since 4-AP and PA are electroactive compounds, extensive interests have been focused on the development of chemically modified electrodes for the detection of them [10], [11], [12], [13], [14], [15], [16], [17], [18].

As a multitalented two-dimensional allotrope of carbon, graphene has attracted absorbing attention, owing to its unique structure and excellent chemical and physical properties [19], [20], [21]. Compared with graphene oxide, graphene exhibits a significant conductivity due to the loss of oxygenated surface groups and defects in the basal plane. So the GO sheets need to be reduced in order to reintroduce the conductivity. The surface of the graphene sample can be fine-tuned to achieve different electronic and optoelectronic properties depending on the level of reduction [22], [23]. In consequence of extraordinary electronic transport property and high electrocatalytic activity [24], [25], graphene has been applied to fabricate electrochemical sensors. Moreover, the electrochemical properties of graphene can be effectively modified by integration with other functional nanomaterials such as catalyst nanoparticles to produce versatile electrochemical sensing performance [26], [27], [28], [29], [30], [31], [32].

Recently, graphene-based nanocomposites have drawn much more interests with the unique properties. And it has drawn exponentially growing interests and hold great promise for many potentially applications [33], [34]. Many graphene-based nanocomposites, such as graphene–polymers [35], graphene–quantum dots [36], graphene–metal oxides [37], and graphene–noble metals [38], have been synthesized and applied in multifarious fields. Among them, palladium catalysts with high catalytic activity and selectivity have come into the view of researchers [39], [40], [41], [42], [43]. As a substitute for Pt catalysts, it was found to have competitive intrinsic electrocatalytic performances compared with Pt-based catalysts. Gold nanoparticles (Au NPs) are the most widely used nanometer materials due to excellent conductivity, goodish catalytic properties and their large specific surface area [44], [45]. Au nanoparticles deposited on the surface of Pd/rGO/GEC can promote electron transfer between acetaminophen, 4-aminophenol and the electrode surface. So, the combination of rGO, Pd Nanocubes (Pd NCs) and Au NPs was expected to provide superior capability for the electrochemical sensor, which can accelerate the reproducibility, stability and electrocatalytic properties of the electrode effectively. And, chitosan (CS), as an important natural biopolymer, due to its good adhesion and good film formation ability, can be used to construct sensors. That is to say, CS can form a film which can fastened Au/Pd/rGO on bare glassy carbon electrode preventing them falling off in order to keeping the stability of the modified electrode.

In the present study, considering the synergetic effect derived from the unique properties of Au, Pd and rGO, a simple and effective approach for the fabrication of Au/Pd/reduced graphene oxide (Au/Pd/rGO) nanohybrid was developed. And the Au/Pd/rGO nanohybrid exhibited excellent electrocatalytic activity for the redox of PA and 4-AP, simultaneously. Based on this, a novel analytical method for simultaneous determination of PA and 4-AP with high performances was developed. Compared with other related methods [49], [50], [51], [52], [53], [54], this proposed sensor possessed lower detection, wider linear range and better selectivity with potential applications.