Amperometric determination of L-cysteine using a glassy carbon electrode modified with palladium nanoparticles grown on reduced graphene oxide in a Nafion matrix
1.Low Dimensional Materials Research Centre, Faculty of Science,University of Malaya,Kuala Lumpur,Malaysia;2.Department of Chemistry,Kalasalingam University (Kalasalingam Academy of Research and Education),Krishnankoil,India;3.Advanced Materials Research Cluster, Faculty of Bioengineering and Technology,Universiti Malaysia Kelantan,Jeli,Malaysia;4.Faculty of Engineering,Xiamen University of Malaysia,Sepang,Malaysia
Abstract:
An amperometric sensor for L-Cys is described which consists of a glassy carbon electrode (GCE) that was modified with reduced graphene oxide placed in a Nafion film and decorated with palladium nanoparticles (PdNPs). The film was synthesized by a hydrothermal method. The PdNPs have an average diameter of about 10 nm and a spherical shape. The modified GCE gives a linear electro-oxidative response to L-Cys (typically at +0.6 V vs. SCE) within the 0.5 to 10 μM concentration range. Other figures of merit include a response time of less than 2 s, a 0.15 μM lower detection limit (at signal to noise ratio of 3), and an analytical sensitivity of 1.30 μA·μM?1·cm?2. The sensor displays selectivity over ascorbic acid, uric acid, dopamine, hydrogen peroxide, urea, and glucose. The modified GCE was applied to the determination of L-Cys in human urine samples and gave excellent recoveries.
Graphical abstract Spherical palladium nanoparticles (PdNPs) on reduced graphene oxide-Nafion (rGO-Nf) films were synthesized using a hydrothermal method. This nanohybrid was used for modifying a glassy carbon electrode to develop a sensor electrode for detecting L-cysteine that has fast response (less than 2 s), low detection limit (0.15 μM), and good sensitivity (0.092 μA μM-1 cm-2).
