One-Step Synthesis of AuPdNPs/ERGO Nanocomposite for Enhanced Electrochemical Sensing of Cr(VI) in Water

Abstract

One-step electrochemical approach for synthesis of AuPdNPs/ERGO nanocomposite has been developed for Cr(VI) sensing in water. The bimetallic AuPd nanoparticles and electrochemical reduced graphene oxide (ERGO) composite (AuPdNPs/ERGO) were reduced from H 2 PdCl 4 , HAuCl 4 and GO mixed solution and deposited onto glass carbon electrode (GCE) through cyclic voltammetry, simultaneously. The bimetallic AuPdNPs were homogeneously modified on graphene nanosheets and characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) technique. Based on the voltammetric results, the bimetallic AuPdNPs/ERGO/GCE had higher catalytic activity for Cr(VI) determination, compared with AuNPs/GCE, PdNPs/GCE and ERGO/GCE obtained by the same method. The fabricated AuPdNPs/ERGO/GCE shows good relationship in two concentration ranges from 0.05 μM to 5 μM and 5 μM to 1000 μM, with a detection of 0.013 μM (at S/N = 3). In addition, the proposed modified electrode presents high selectivity, sensitivity and stability for Cr(VI) detection and a high recovery of more than 95% was obtained towards real water application, which makes it favorable for the further practical field monitoring.

Recent progress regarding electrochemical sensors for the detection of typical pollutants in water environments

“…101 Hu et al developed a one-step electrochemical synthesis of AuPdNPs/rGO nanocomposites and deposited them on GCE electrodes by cyclic voltammetry. 102 Except for the two modified electrodes mentioned above, when detecting actual water samples, HCl is used to adjust the pH of the water sample to be tested to strong acidity. In most other literature, HNO₃, H₂SO₄ or HClO4 are also used to adjust the pH of the solution.…”

Review—Graphene-Based Water Quality Sensors

“…This challenge has been well received by the scientific community and multiple novel sensing strategies have been reported, with an emphasis on simple and fast quantification. Recent examples of these strategies include optical methods for the detection of heavy metals, [30][31][32][33] plasmon resonance sensors for monitoring pesticides, 34 amperometric methods for the quantification of nitrite, 35 and voltammetric sensors for the detection of heavy metals, [36][37][38][39] uranium, 40 E. coli, 41 nitrate 42 and sulfite. 43 The most desirable type of sensors for monitoring water quality are low-maintenance online sensors that can operate continuously, autonomously, and reagent-free.…”

Recent Advances in Electrochemical Monitoring of Chromium

“…Honggui Wang et al [76] In another approach, the bimetallic AuPd nanoparticles and reduced graphene oxide were also utilized in the construction of a composite sensor intended for Cr(VI) measurement [77]. Owing to the numerous advantages among them facile preparation process (One-step electrochemical approach), high selectivity, sensitivity and stability, the prepared sensor showed great potential for the Cr(VI) monitoring with recovery more than 95% in lake and river waters and 0.676 µg•L −1 as the lowest detected concentration.…”