Simultaneous In Situ Extraction and Self-Assembly of Plasmonic Colloidal Gold Superparticles for SERS Detection of Organochlorine Pesticides in Water

Abstract

Rapid component separation and reliable surface-enhanced Raman scattering (SERS) detection of organochlorine pesticide (OCP) residues in real water samples remain major challenges because of sample complexity, trace content, and low molecular affinity for a metal surface. Here, we report a novel strategy of simultaneous in situ extraction and fabrication of plasmonic colloidal gold superparticles (AuSPs) to perform rapid SERS detection of OCPs in environmental water. In this protocol, multiple components of OCPs in complex water were facilely diffused into dichloromethane (DCM) microdroplets and specifically bound to octadecylamine-modified gold nanoparticles (Au-ODAs), affording the SERS substrate through self-assembly of the OCP-trapped Au-ODA into AuSPs with the evaporation of DCM. SERS signals of the specifically prepared Au-ODA could be used as an internal standard to calibrate the absolute signal of OCPs, and multiplex detection could be achieved depending on their molecularly narrow Raman peaks. As for simultaneously sensing four kinds of OCPs (4,4′-DDT, α-endosulfan, tetradifon, and chlordane) in water, the established method showed strong anti-interference ability and comparable quantification ranges with a low limit of detection (LOD). The recoveries ranged from 90.20 to 109.4% for OCPs in farmland, river, and fishpond water, indicating that the established AuSP-based platform is reliable and applicable to the detection of OCPs in real water samples.

Towards practical and sustainable SERS: a review of recent developments in the construction of multifunctional enhancing substrates

“…A simple and reproducible method that can be used in-field with no specialist equipment to extract and enrich hydrophobic dipolar molecules from complex aqueous samples is liquidliquid extraction. [144][145][146] For example, Liu, Tan, et al showed that simply shaking fruit juice spiked with thiabendazole with chloroform allowed rapid extraction of the dipolar pesticide from the juice sample into chloroform. 147 As shown in Figure 10A, the separated thiabendazole chloroform solution could be used directly as the oil phased for nanoparticle self-assembly by mixing and shaking it with a colloidal solution of Au nanorods (see section 2.3 for detail mechanism).…”

“…Au superparticle [144] liquid-liquid extraction farmland, river and fishpond water: unknown contaminants nM (αendosulfan) silicon nanowire array decorated with Ag nanodendrite [157] TLC milk: competitively adsorbing proteins melamine LOD: 2.5 ppm unspecified Au sputtered chromatography paper [159] paper chromatography superhydrohobic Au NPs/nickel foam [165] hydrophobic interactions (1-naphthol) Raman reporter labelled Au NPs-based lateral flow assay strip [174] bio-recognition bacterial pathogen solution: unknown bio-contaminants [176] hydrogen bonding milk: competitively adsorbing proteins; tab water: unknown contaminants 2,4dichlorophenoxyacetic acid demonstrated 1 ng/mL in milk and tab water 0.00147 ng/mL PEG-S functionalized Au triangular nanoprisms patch [180] antifouling diluted human plasma: biocontaminants, mainly protein fentanyl, 4-ANPP, cocaine, heroin, cannabinoids LOD: 3.0 pg/mL (fentanyl); demonstrated 1 nM (4-ANPP, cocaine, heroin, cannabinoids) unspecified metal NPs embedded hydrogel micropellet [186] size exclusion milk: competitively adsorbing proteins; whole blood: biocontaminants, mainly protein melamine, glucose LOD: 10 nM (melamine in milk); 0.01 mM (glucose in whole blood) LOD: 0.01 mM (glucose) polydopamine@Au nanowaxberry [191] size exclusion soil: particulate matter thiram LOD: 0.31 µg/g LOD: 0.5 nM the adenine molecules within the plasmonic hot spots, as illustrated in Figure 13H, which led to a 3× SERS signal increase compared to contrast experiments performed without protein.…”

Au/Ag Bimetallic Nanocuboid Superlattices Coated with Ti3C2 Nanosheets for Surface-Enhanced Raman Spectroscopy Detection of Fish Drug Residues in Pond Water

“…For example, Yang et al 12 developed a molecular imprinting-based detection method for paclobutrazol. Chen et al 13 simultaneously extracted and detected organochlorine pesticides in water by colloidal gold superparticles. However, the traditional methods have difficulty in simultaneously realizing both high sensitivity and multiple detection ability.…”

Simultaneous and Accurate Quantification of Multiple Antibiotics in Aquatic Samples by Surface-Enhanced Raman Scattering Using a Ti3C2Tx/DNA/Ag Membrane Substrate

“…11 Through identification and screening of quantitative peaks of multiple targets, it has the potential to realize simultaneous analysis of multiple targets. 12 However, most current reports on simultaneous SERS analysis remained at the qualitative or semiquantitative level and there are no simultaneous quantitative analyses of multiple targets in complex samples. 13−16 The main reason is attributed to the difficultly of finding characteristic quantitative SERS peaks that do not interfere with those of each target, since the complex matrix composition of real samples would usually cause the serious overlapping of target SERS spectra due to the lack of a separation function of the SERS technology.…”

“…It has good sensitivity, is a portable instrument, and shows little interference from water and fluorescence. − In addition, it can provide the fine fingerprint of the target and present rich structural information . Through identification and screening of quantitative peaks of multiple targets, it has the potential to realize simultaneous analysis of multiple targets . However, most current reports on simultaneous SERS analysis remained at the qualitative or semiquantitative level and there are no simultaneous quantitative analyses of multiple targets in complex samples. − The main reason is attributed to the difficultly of finding characteristic quantitative SERS peaks that do not interfere with those of each target, since the complex matrix composition of real samples would usually cause the serious overlapping of target SERS spectra due to the lack of a separation function of the SERS technology. − Therefore, in order to realize high-throughput and accurate rapid analysis by SERS, it is necessary to develop excellent SERS substrates with good selectivity and high sensitivity for simultaneous analysis of multiple targets.…”