Highly sensitive pesticide detection using electrochemically prepared Silver-Gum Arabic nanocluster SERS substrates

Surface Enhanced Raman is a promising analytical method for harmful pesticides detection. Herein, we demonstrate a rapid method to directly monitor 2,4-D pesticide in water environment without the need of sample pre-treatment by using Silver-Gum Arabic (Ag-GA) electrochemically co-deposited SERS substrates. This electrochemical synthesis of large-area (40 µm x 20 µm), high nano particle density, and homogeneous SERS substrates needs as little as 2 µL AgNO₃ and Gum Arabic mixed solution by a portable potentiostat. Different morphologies including Ag-GA spherical nanoparticles and nano dendrites were synthesized by tuning the deposition parameters. This study therefore offers a novel way to fabricate SERS substrates for determination of 2,4-D pesticides down to 1 pM in half hour and down to 0.001 nM immediately in deionized water, 0.15 nM in commercial bottled and also river water samples. This Ag-GA SERS sensor showed linear response towards 2,4-D detection in a wide linear range.