Gold Nanoparticle-Coated ZrO2-Nanofiber Surface as a SERS-Active Substrate for Trace Detection of Pesticide Residue

Abstract

Trace detection of common pesticide residue is necessary to assure safety of fruit and vegetables, given that the potential health risk to consumers is attributed to the contamination of the sources. A simple, rapid and effective means of finding the residue is however required for household purposes. In recent years, the technique in association with surface-enhanced Raman scattering (SERS) has been well developed in particular for trace detection of target molecules. Herein, gold nanoparticles (Au NPs) were integrated with sol-gel spin-coated Zirconia nanofibers (ZrO2 NFs) as a chemically stable substrate and used for SERS application. The morphologies of Au NPs/ZrO2 NFs were adjusted by the precursor concentrations (_X, X = 0.05–0.5 M) and the effect of SERS on Au NPs/ZrO2 NFs_X was evaluated by different Raman laser wavelengths using rhodamine 6G as the probe molecule at low concentrations. The target pesticides, phosmet (P1), carbaryl (C1), permethrin (P2) and cypermethrin (C2) were thereafter tested and analyzed. Au NPs/ZrO2 NFs_0.3 exhibited an enhancement factor of 2.1 × 107, which could detect P1, C1, P2 and C2 at the concentrations down to 10−8, 10−7, 10−7 and 10−6 M, respectively. High selectivity to the organophosphates was also found. As the pesticides were dip-coated on an apple and then measured on the diluted juice containing sliced apple peels, the characteristic peaks of each pesticide could be clearly identified. It is thus promising to use NPs/ZrO2 NFs_0.3 as a novel SERS-active substrate for trace detection of pesticide residue upon, for example, fruits or vegetables.

Ag Nanostructures with Spikes on Adhesive Tape as a Flexible Sers-Active Substrate for In Situ Trace Detection of Pesticides on Fruit Skin

“…However, it is equally important to note that off-resonance enhancement conditions could occur and provide even better enhancement than resonant conditions [18,19]. The EF value, referred to our previous method [20] was calculated to be 1.7 × 10 7 owing to the optimal agglomeration of Ag NSPs, which is considered typical to currently-developed SERS substrates that were also designed for pesticide detection [3,15,21].…”

“…The enhancement of Raman signals in SERS is driven by electromagnetic (EM) or chemical (CM) mechanism [3], brought about by the analytes being in close proximity with hot spots located at the gaps among the PNSs, and the electronic properties of the analyte being modified from the formation of metal-analyte complexes, respectively. The contribution by EM to the enhancement effect is more than that of CM, and it is based on the excited state of LSPR as induced by the incident light onto the metal surface, thus this mechanism is dependent on the physical attributes (shape, size, and material/s) of PNSs.…”

One-step controllable synthesis of three-dimensional WO3 hierarchical architectures with different morphologies decorated with silver nanoparticles: enhancing the photocatalytic activity

“…), is an effective and suitable way to control size, shape, crystalline structure and composition of the hierarchical crystals. [6][7][8][9][10] These hybrid hierarchical architecture materials offer a wide range of technological applications including development of smart materials or intelligent systems; development of materials for application in nanobiotechnology, optoelectronics, sensors, solar cells, and photocatalysis. [11][12][13][14] In addition, the presence of the noble metal nanoparticles can inuence the morphology and properties of materials.…”

Dielectric Nanoparticles Coated upon Silver Hollow Nanosphere as an Integrated Design to Reinforce SERS Detection of Trace Ampicillin in Milk Solution

“…A substrate with integrated plasmonic and dielectric components was designed to increase the adsorption of target species and to repulse non-specific binding molecules from SERS-active sites.Coatings 2020, 10, 390 2 of 15 techniques to provide rapid, food quality preserved, and bio-safety evaluation or analysis for related laboratories or industries [9][10][11].Surface-enhanced Raman scattering (SERS) technique delivers fingerprint information about a given substance using nearly roughened metal surfaces, metal nanoparticles (NPs), or metal nanostructures owing to their strong effect on the Raman-active peak(s) of target molecule. The enhancement of Raman-active modes is mainly due to the contribution of two effects through chemical mechanism (CM) and electromagnetic mechanism (EM) [12][13][14][15]. The CM depends on the adsorption of target molecules upon the "hot spots", which are generated at SERS-active sites; charge transfer occurs between the target molecule and the substrate, which may be enhanced by the polarizability of the molecule [16].…”

“…Surface-enhanced Raman scattering (SERS) technique delivers fingerprint information about a given substance using nearly roughened metal surfaces, metal nanoparticles (NPs), or metal nanostructures owing to their strong effect on the Raman-active peak(s) of target molecule. The enhancement of Raman-active modes is mainly due to the contribution of two effects through chemical mechanism (CM) and electromagnetic mechanism (EM) [12][13][14][15]. The CM depends on the adsorption of target molecules upon the "hot spots", which are generated at SERS-active sites; charge transfer occurs between the target molecule and the substrate, which may be enhanced by the polarizability of the molecule [16].…”