SERS spectrum of imazalil. Experimental and quantum‐chemical vibrational analysis

Abstract

Imazalil [1‐[2‐(2,4‐dichlorophenyl)‐2‐(2‐propenyloxyl‐ethyl]‐1 H imidazole] is a systemic fungicide that is toxic to a number of plant pathogens, particularly species of Penicillum. Its activity is based on the inhibition of mold sporulation on fruit skin, which makes it one of the most commonly used fungicide in post‐harvest citrus treatments for fruit preservation during storage, shipping, and marketing. Due to its wide application, the presence of imazalil needs to be monitored to avoid the excessive and/or improper use. This work reports a complete analysis of the Fourier‐transform infrared spectroscopy and Raman spectra of imazalil as a pure compound as well as in the commercial product for agricultural use; the band assignment relays in the vibrational predictions acquired by quantum‐chemical calculations (B3LYP/6–311 + g(2df, p)) for the imazalil molecule. An analytical application of surface‐enhanced Raman spectroscopy (SERS) is also presented here. It is done so by using a novel, low‐cost, and sensitive SERS‐active substrate built with silver nanoparticles supported on a Si/ZnO nanowires platform to detect traces of imazalil in aqueous solutions. Comparison between the Raman and SERS spectra allowed the characterization of the interaction between the pesticide and the silver nanoparticle surface.

A brief review of recent advances in surface-enhanced Raman spectroscopy and microfluidics technology for the ultrasensitive detection of pesticides.

“…Despite immunoassays [17], electrochemical methods [13], and capillary electrophoresis [18] are common rapid detection techniques, they also suffer from some inherent flaws, like instability of the solution and limited stocking time [19]. Surface-enhanced Raman spectroscopy (SERS) is an emerging detection technology, based on label-free detection method capable of providing high sensitivity, offering remarkable possibilities for analytical applications in fast and simple protocols and relatively inexpensive experiments [20]. detecting OPs substances.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

“…Diaz‐Miron and co‐workers carried out a vibrational analysis of the SERS spectrum of imazalil. Both experimentally measured and quantum‐chemically caculated spectra were compared, which allowed the characterization of the interaction between the pesticide and the silver NP surface . Gonzalez Fa reported a SERS and density functional theory (DFT) comparison of silver NPs synthetized with d ‐glucose.…”

“…Both experimentally measured and quantumchemically caculated spectra were compared, which allowed the characterization of the interaction between the pesticide and the silver NP surface. [26] Gonzalez Fa reported a SERS and density functional theory (DFT) comparison of silver NPs synthetized with D-glucose. Their results reveals a preference for D-gluconate anion acting as capping agent under the necessary presence of D-glucose on the surface of the AgNPs.…”

Gold nanoparticle-based immunochromatographic assay for rapid detection of imazalil

“…For example, methods based on surfaceenhanced Raman spectroscopy (SERS) have been reported for IMZ detection in fruits recently. [21][22][23] Immunoassay is an alternative approach to achieve the rapid detection of analytes, with high throughput. Based on the specific and sensitive binding affinity between the antibody and antigen, immunoassays usually offer great performance for the analysis of agricultural chemicals in real samples, such as insecticides, 24,25 herbicides, 26,27 acaricide, 28 and fungicides.…”