In-Situ Synthesis of Methyl Cellulose Film Decorated with Silver Nanoparticles as a Flexible Surface-Enhanced Raman Substrate for the Rapid Detection of Pesticide Residues in Fruits and Vegetables.

Qijia Zhang,Tongtong Wang,Na Guo,Peng Song,Guangda Xu,Lixin Xia

doi:10.3390/ma14195750

Qijia Zhang, Tongtong Wang + Show 4 more

Open Access

https://doi.org/10.3390/ma14195750

Copy DOI

Journal: Materials	Publication Date: Oct 1, 2021
Citations: 10	License type: CC BY 4.0

Affiliation: Liaoning University, Yingkou Institute of Technology

Abstract

The purpose of this study was to develop a flexible substrate methylcellulose-decorated silver nanoparticles (MC/Ag NPs) film and explore its application in fruits and vegetables by surface enhanced Raman spectroscopy (SERS) technology for rapid detection of pesticides. The performance of the MC/Ag NPs film substrate was characterized by Nile blue A (NBA), and the detection limit was as low as 10−8 M. The substrate also exhibited satisfactory Raman signal strength after two months of storage. The impressive sensitivity and stability were due to the excellent homogeneity of the silver nanoparticles that were grown in situ in the methylcellulose matrix, which generated “hot spots” between the silver nanoparticles without a large amount of aggregation, and resulted in the ultra-high sensitivity and excellent stability of the MC/Ag NPs film substrate. The MC/Ag NPs film substrate was used to detect thiram pesticides on tomato and cucumber peels, and the minimum detectable level of thiram was 2.4 ng/cm2, which was much lower than the maximum residue level. These results indicate that the MC/Ag NPs film is sensitive to rapid detection of multiple pesticides in food.

Highlights

Pesticide residues in foods have attracted much attention in recent years as consuming fruits and vegetables that are contaminated with pesticides can cause potential health problems, such as poisoning [1]
We developed a simple strategy to maintain the SERS activity of a substrate using the in situ growth of silver nanoparticles in a methylcellulose matrix as a film (MC/Ag NPs film)
Methyl cellulose (MC), Nile Blue A (NBA), and thiram pesticides were purchased from Aladdin Industrial Co. (Shanghai, China)

Summary

Introduction

Pesticide residues in foods have attracted much attention in recent years as consuming fruits and vegetables that are contaminated with pesticides can cause potential health problems, such as poisoning [1]. Common methods of analyzing pesticide residues include high performance liquid chromatography (HPLC) [2] and gas chromatography (GC) combined with different detection techniques [3]. Such methods are sensitive, standardized, and are common, and are regarded as the gold standard [4] for pesticide detection. These analytical methods have some drawbacks, such as complex pre-processing steps, time-consuming analytical processes, professional technicians, and the need for large and expensive instrumentation. SERS technology has the ability to accurately identify the signal fingerprints of analytes, and it can be applied to multiple fields

Objectives

Methods

Results