Development of a single aptamer-based surface enhanced Raman scattering method for rapid detection of multiple pesticides

Abstract

The objective of this study was to develop a simple and rapid method that could detect and discriminate four specific pesticides (isocarbophos, omethoate, phorate, and profenofos) using a single aptamer-based capture procedure followed by Surface Enhanced Raman Spectroscopy (SERS). The aptamer is a single stranded DNA sequence that is specific to capture these four pesticides. The thiolated aptamer was conjugated onto silver (Ag) dendrites, a nanostructure that can enhance the Raman fingerprint of pesticides, through Ag-thiol bonds. It was then backfilled with 6-mercaptohexanol (MH) to prevent nonspecific binding. The modified SERS platform [Ag-(Ap + MH)] was then mixed with each pesticide solution (P) for 20 min. After capturing the pesticides, the Ag-(Ap + MH)-P complex was analyzed under a DXR Raman microscope and TQ Analyst software. The results show that the four pesticides can be captured and detected using principal component analysis based on their distinct fingerprint Raman peaks. The limits of detection (LODs) of isocarbophos, omethoate, phorate, and profenofos were 3.4 μM (1 ppm), 24 μM (5 ppm), 0.4 μM (0.1 ppm), and 14 μM (5 ppm) respectively. This method was also validated successfully in apple juice. These results demonstrated the super capacity of aptamer-based SERS in rapid detection and discrimination of multi-pesticides. This technique can be extended to detect a wide range of pesticides using specific aptamers.

Investigation of the solubility enhancement mechanism of rebaudioside D using a solid dispersion technique with potassium sorbate as a carrier

“…Principal Component Analysis (PCA) was performed using TQ Analyst (Version 8.0) to evaluate the variance between spots (within class) and samples (between classes) (Pang, Labuza, & He, 2014;Wang, He, Labuza, & Ismail, 2013). Samples were considered to be significantly different (p<0.05) when all spots were clustered and separated from another sample.…”

Paper-based diagnostic devices for clinical paraquat poisoning diagnosis

“…40,41 Nowadays, the development of simple pesticide biosensors mainly focuses on the quantification of organophosphorus or carbamate compounds in food or water because both pesticides are widely used in agriculture. [42][43][44] PADs as pesticide detection devices may use photoelectrochemical or colorimetric assay platforms to indicate the presence of organophosphorus or carbamate pesticides to secure food quality. [45][46][47] Notably, we, and others, have developed PADs to analyze serum organophosphate level for organophosphate poisoning in patients.…”

Aptamer-Based Technology for Food Analysis

“…Wang et al [109] isolated ssDNA aptamers against four organophosphorus pesticides (phorate, profenofos, isocarbophos, and omethoate), which offered application potential in the analysis and neutralization of the residues of the four organophosphorus pesticides. Indeed, using a single aptamer-based surface-enhanced Raman scattering method, Pang et al [111] realized the detection and discrimination of four specific pesticides (isocarbophos, omethoate, phorate, and profenofos), with the limits of detection 3.4, 24, 0.4, and 14 μM, respectively. This method was validated in apple juice, demonstrating the great potential of aptamer-based sensors as analytical tools for rapid detection and discrimination of multipesticides.…”