Application of surface-enhanced Raman spectroscopy using silver and gold nanoparticles for the detection of pesticides in fruit and fruit juice

Background: Pesticide residues are known to cause serious problems to human health. Although the detection of pesticides in fruit and fruit juice has been traditionally attempted using chromatographic techniques, surfaceenhanced Raman spectroscopy (SERS) has recently arisen as a suitable alternative for the detection of organic compounds in biological matrices. Scope and approach: All reported methods for the detection of pesticides in fruit and fruit juice, based on SERS enhanced with gold and silver nanoparticles, are covered for the first time. The detection parameters obtained using different experimental conditions are compared throughout the manuscript. The achievements and limitations of this technique for the detection of pesticides in fruit and fruit juice are discussed. Key findings and conclusions: A variety of sample preparation steps, scaffolds for the deposition of nanoparticles, nanoparticles with different shapes and decorations, and metal combinations were screened across the reports. The decoration of the nanoparticles with organic structures, such as mercaptooctanone and polyvinyl alcohol, and combinations with WO3, WS2 and MoS2 provided high sensitivity and stability. The developed methods were used for the detection and quantification of numerous pesticides in different matrices and showed similar limits of detection in comparison with traditional chromatographic methods. Interestingly, SERS allowed the detection of cations and organometallic structures that are difficult to detect with other techniques. In contrast with traditional methods, methods based on Raman spectroscopy allow the detection of only one or a few pesticides simultaneously, and the simultaneous quantification of several pesticides requires the introduction of a preliminary separation step.

Automated summary

This study comprehensively covers all reported methods for the detection of pesticides in fruit and fruit juice using SERS enhanced with gold and silver nanoparticles, comparing detection parameters obtained under different experimental conditions. The achievements and limitations of this technique for pesticide detection in fruit and fruit juice are discussed.