This research presents a successful fabrication of highly periodic Cu microbead arrays on Ag layer on screen printed carbon electrode (CASS) for dual mode detection of hazardous pesticide GLP. This is first report demonstrating a commercial SPCE electrode reinforced with Cu and Ag material used for electrochemical and SERS detection of glyphosate (GLP).

Technology Overview
Dual mode sensor is developed for electrochemical and SERS detection of glyphosate. Sensor is equipped with periodic Cu microbead arrays on Ag layers (CASS). CASS shows a wide operating range (0.5 to 772.5 µM) for electrochemical mode. CASS offers high enhancement factor (10⁸) for SERS mode. Good detection limit is obtained for electrochemical (10^-9 M) and SERS (10^-11) mode.

Applications & Benefits
CASS eliminates the background luminescence during analysis as they have different reference wavelength and their overlapping surface plasmonic effect helps in attaining enhanced Raman spectra. The CASS has potential to be deployed for real time analysis in agricultural and food sectors for monitoring pesticides.

Abstract：
In this research, periodic Cu microbead arrays on Ag layer (CASS) for dual mode detection of glyphosate (GLP) is developed. CASS is fabricated on screen printed carbon electrodes though electroplating technique and characterized thoroughly to understand the morphology. Average size of Cu bead is 280 µm and distance between beads is found to be 100 µm through scanning electron microscopy (SEM) analysis. Periodicity of Cu microbead arrays enhanced the overall catalytic activity for both electrochemical and SERS modes. Wide detection range of 0.5 – 772.5 μM is obtained for electrochemical mode and a superior enhancement factor in the range of 10⁸ is achieved in SERS mode. Further, both electrochemical and SERS modes showed an excellent limit of detection (10^-9 M and 10^-11 M) for GLP. Also excellent stability and reproducibility of CASS is observed for electrochemical mode for 10 day period towards GLP detection and with respect to SERS, many random spots on CASS are tested for reproducible GLP SERS signal. CASS sensor promises to be a good prospect for portable, cost effective and on the spot detection of lethal pesticides.

Periodic copper microbead array on silver layer for dual mode detection of glyphosate
Author：Ramachandran Balaji, Vengudusamy Renganathan, Chia-Pei Chu, Ying-Chih Liao, C.R. Kao, Shen-Ming Chen
Year：2022
Source publication：OpenNano Volume 8, November–December 2022, 100105
Subfield Highest percentage：99%    Pharmaceutical Science   #2/171

https://www.sciencedirect.com/science/article/pii/S2352952022000676