Development of a bimodal sensor based on upconversion nanoparticles and surface-enhanced Raman for the sensitive determination of dibutyl phthalate in food

Phthalate acid esters (PAEs) are commonly used as plasticizers in several products. Unfortunately, they can easily leak into the environment, foods and enrich in body, eventually cause harm to human health. Hence, a rapid and sensitive method for the detection of PAEs in food is necessary. This study introduces a facile fabrication of a bimodal nanocomposite by coupling surface-enhanced Raman scattering (SERS) and upconversion fluorescence as signal for the sensitive detection of PAEs. The proposed sensor was based on upconversion nanoparticles (UCNPs) decorated with gold nanoparticles (AuNPs). The UCNPs were used as the signal molecule, meanwhile, the AuNPs served as the SERS substrate, and the aptamer was applied as an identification tag for PAEs. Interestingly, the limit of detection (LOD) of fluorescence and SERS methods were calculated as 0.0087 ng/mL and 0.0108 ng/mL, respectively. The developed assay was successfully applied to spiked food samples and food packagings. These results demonstrated the dual-mode investigation and the strategy has potential for the selective detection and quantification of PAEs in food samples.

Automated summary

A bimodal nanocomposite using surface-enhanced Raman scattering (SERS) and upconversion fluorescence was developed for the sensitive detection of PAEs in food samples. The dual-mode investigation strategy showed potential for selective detection and quantification of PAEs.