Detection of Dithiocarbamate Pesticides with a Spongelike Surface-Enhanced Raman Scattering Substrate Made of Reduced Graphene Oxide-Wrapped Silver Nanocubes

Abstract

Dithiocarbamate (DTC) pesticides are widely used for fruits, vegetables, and mature crops to control fungal diseases. Their residues in food could pose a threat to human health. Therefore, a surface-enhanced Raman scattering-based (SERS-based) sensor is developed to detect DTC pesticides because SERS can provide the characteristic spectrum of pesticides and avoid the use of a molecular recognition probe in the sensor. For the acquisition of high sensitivity, good anti-interference ability, and robustness of the SERS sensor, a silver nanocube-reduced graphene oxide (AgNC-rGO) sponge is devised. In the AgNC-rGO sponge, the rGO sheets form a porous scaffold that physically holds the AgNCs, which create narrow gaps between the neighboring AgNCs, leading to the formation of "hot spots" for SERS-signal amplification. When DTC pesticides coexist with aromatic pesticides in a sample matrix, the AgNC-rGO sponge can selectively detect DTC pesticides because of the preferential adsorption of DTC pesticides on the Ag surface and aromatic pesticides on the rGO surface, which can effectively eliminate the interference of the SERS signals of aromatic pesticides, and facilitate the qualitative and quantitative analysis of DTC pesticides. The AgNC-rGO sponge shows great potential as a SERS substrate for selective detection of DTC pesticides.

4-Mercaptobenzoic Acid Labeled Gold-Silver-Alloy-Embedded Silica Nanoparticles as an Internal Standard Containing Nanostructures for Sensitive Quantitative Thiram Detection

“…Compared with HPLC-MS, SERS does not require harsh solvents and a high power source, and it is easily compatible with other detection systems [21]. As a result, many studies have focused on the use of different nanoparticles (NPs) as substrates for SERS detection of pesticides, such as silver nanostructures [21,22,23,24,25,26], gold nanostructures [27,28,29,30,31], and graphene oxide [32,33]. Although these nanostructures could enhance the SERS signal up to 10 14 times, the practical application of SERS exhibits some technical challenges in the fabrication of reproducible, reliable, and robust SERS-active surfaces.…”

Mussel-Inspired Fabrication of SERS Swabs for Highly Sensitive and Conformal Rapid Detection of Thiram Bactericides

“…Thiram, an important member of dithiocarbamate bactericides, has been widely used in agriculture fields to protect fruit, vegetable, ornamental plants and crops from various fungal diseases [1,2,3]. In addition, it is also used as a protective fungicide and animal repellent to preserve mature fruits and vegetables during storage and shipment [4].…”

Chemometric Calibration of Surface enchanced Raman Spectra for Quantitative Analysis

“…Both cases are derived from the spectrum-concentration study of DTC pesticides performed by Zhu et al [10].…”

“…The real data involved in this paper is from Zhu et al [10]. It includes the study of the mixture of two materials: ferbam and thiram.…”

“…Raman signals are generated by the inelastic scattering of the incident light from a sample and are also known as Raman spectrum, which enables both qualitative and quantitative analysis [6,7]. The characteristic fingerprinting pattern in a Raman spectrum renders the possibility to identify substances and quantify analyted concentrations [8,9,10,11]. For example, in a most recent study, Raman spectrum was applied to measure the concentrations of cocaine, cannabis and alcohol from human saliva [12,13].…”