Wireless electrochemical sensor for the detection of phytoregulator indole-3-acetic acid using gold nanoparticles and three-dimensional reduced graphene oxide modified screen printed carbon electrode

Plant hormones are important regulatory substances in crop growth and production. In this work, a wireless electrochemical sensor has been successfully established by using gold nanoparticles and three-dimensional reduced graphene oxide (AuNPs-3DGR) modified screen printed carbon electrode (SPCE) to detect plant regulator indole-3-acetic acid (IAA) in plants. AuNPs-3DGR nanocomposite was prepared by reduction of ultrasonic assisted liquid phase dispersed graphene oxide (GO) and Au3+ mixture using hydrothermal method. The composite was modified on SPCE by drop coating, and the wireless portable electrochemical workstation that controlled by smartphone was used to detect IAA with a wider linear ranges (0.25–120.0 μmol/L and 135.0–500.0 μmol/L) and a lower limit of detection (0.15 μmol/L, 3σ/S). After that, this sensor was applied to detect the IAA content in different tissues of mung bean sprouts with satisfactory results. The combination of modified SPCE with small bluetooth workstations and smartphone is very useful to construct portable, low-cost, simple and fast electrochemical sensing platform.