A Plasmonic Sensor Based Gold Nanoparticles for Detection of Chlorpyrifos
Suratun Nafisah (a,b), Nur Farah Wahidah Fauzi (b), Nur Liyana Razali (b,c), Mitra Djamal (d), Marlia Morsin (b,c*)

a) Departement of Electrical Engineering, Faculty of Industrial and Production Technology, Institut Teknologi Sumatera (ITERA), Lampung Selatan, 35365 Indonesia
b) Department of Electronic Engineering, Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor, Malaysia
c) Microelectronics & Nanotechnology - Shamsuddin Research Centre (MiNT-SRC), Institute of Integrated Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat Johor, Malaysia
*marlia[at]uthm.edu.my
d) Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung - 40132, Indonesia

Abstract

Plasmonic sensor-based gold nanoparticles (GNPs) have been developed for detecting organophosphorus pesticides namely chlorpyrifos. Chlorpyrifos is the most common-used pesticide in agriculture (including soybeans, apples, broccoli, and corn) and non-agriculture like golf courses. The GNPs have been used as sensing materials in this sensor setup and were synthesized and deposited as a thin film using the seed-mediated growth method (SMGM). In this study, the sensitivity of the plasmonic sensor^s effect and response to two different mediums which are deionized (DI) water and chlorpyrifos as targeted analytes were successfully detected by recording the changes in peak positions and intensities for transverse Surface Plasmon Resonance (t-SPR) and longitudinal SPR (l-SPR). The change in response is due to changes in the refractive index of the surrounding medium, which are water (n = 1.33) and chlorpyrifos (n = 1.56). The SPR red-shifted to a longer wavelength as the refractive index of the surrounding medium increased as well as the concentration increased from 1 mg/mL to 10 mg/mL. Furthermore, the stability of GNPs in the presence of different analytes was tested for 600 seconds and it was found that the changes in peak intensity for both peaks were minimal. The response of the repeatability test is consistent over five testing cycles, as indicated by DI water and analyte intensities that almost completely recover to their previous levels after every cycle of medium change.

Keywords: Chlorpyrifos- Gold nanoparticles (GNPs)- Plasmonic sensor

Topic: Theory and Design