Rapid detection of multiple organophosphorus pesticides (triazophos and parathion-methyl) residues in peach by SERS based on core-shell bimetallic Au@Ag NPs

ABSTRACT

In this study, a surface-enhanced Raman scattering (SERS) approach based on silver-coated gold nanoparticles (Au@Ag NPs) was established for rapid detection of multiple organophosphorus pesticides (triazophos and methyl-parathion) in peach fruit. The Raman enhancement of Au@Ag NPs for detecting organophosphorus pesticides was stronger than those of single Ag and Au NPs. It was revealed that core size of Au NPs was a critical parameter affecting the enhancement of Raman signals by joining two plasma resonance absorptions. The Au@Ag NPs with 26 nm Au core size and 6 nm Ag shell thickness showed significant Raman enhancement, especially by the creation of hot spots through NPs aggregation induced by connection between Au@Ag NPs and target molecules. The detection limits of triazophos and methyl-parathion in peach were 0.001 mg/kg. Good recovery (93.36 to 123.6 %) and high selectivity of the SERS activity allowed excellent precision for the detection of the triazophos and methyl-parathion in peach. Compared to earlier studies, the current approach was rapid, inexpensive and simple without lengthy sample pre-treatment. This study revealed that the proposed method could be employed for the analysis of trace contaminants such as triazophos and methyl-parathion in many food matrices.

KEYWORDS:

• SERS
• residue detection
• triazophos
• methyl-parathion
• substrate
• fruit
• core-shell nanoparticles

Acknowledgments

The authors are grateful to the National Key R&D Program of China (2018YFC1603404) for its support. This research was also supported by the Fundamental Research Funds for the Central Universities (2018MS056, 2017MS075), the International and Hong Kong – Macau - Taiwan Collaborative Innovation Platform of Guangdong Province on Intelligent Food Quality Control and Process Technology & Equipment (2015KGJHZ001), the Guangdong Provincial R & D Centre for the Modern Agricultural Industry on Non-destructive Detection and Intensive Processing of Agricultural Products, the Common Technical Innovation Team of Guangdong Province on Preservation and Logistics of Agricultural Products (2016LM2154) and the Innovation Centre of Guangdong Province for Modern Agricultural Science and Technology on Intelligent Sensing and Precision Control of Agricultural Product Qualities. In addition, Tehseen Yaseen is in receipt of a PhD scholarship from the China Scholarship Council (CSC).

Disclosure statement

No potential conflict of interest was reported by the authors.