Rapid detection of tebuconazole based on hydrogel SERS chips

Tebuconazole is one of the most commonly used fungicides in agricultural production, that has the merits of highly effectiveness, broad spectrum and systemic function. Excessive tebuconazole may pose a great threat to human and animal health. Traditional detection techniques for tebuconazole usually have limitations such as expensive equipment, poor antibody stability, and time-consuming procedures. Herein, a sensitive sensor is developed for the rapid detection of tebuconazole based on hydrogel surface-enhanced Raman scattering (SERS) chips. Aggregated Ag nanoparticles (a-AgNPs) with tunable localized surface plasmon resonance (LSPR) wavelength are in-situ synthesized in polyvinyl alcohol (PVA) solution for preparing hydrogel SERS chips. Three hydrogel SERS chips are obtained to match the three commonly used laser wavelengths. On the basis, a match laser wavelength is selected according to the energy levels of tebuconazole and the Fermi level of a-AgNPs to gain a strong chemical enhancement. At the same time, the chip with a corresponding LSPR wavelength to the laser is applied to obtain a strong electromagnetic enhancement. Thus, highly sensitive SERS signal of tebuconazole is obtained. Furthermore, the obtained hydrogel SERS chips have good repeatability, outstanding reproducibility and strong anti-interference ability, and show outstanding reliability in practical applications. As a result, the SERS chips offer a reliable and convenient platform for the quick detection of tebuconazole in foods. The detection limit is as low as 1 ppb, and the recoveries is distributed in the range of 94.66–106.70 %. This work would promote greatly the application of SERS in small molecule detection. Aggregated silver nanoparticles (a-AgNPs) were synthesized in situ in PVA hydrogels by tuning the local surface plasmon resonance of a-AgNPs by carbon dots tuned to match three commonly used laser wavelengths, namely 532, 633 and 785 nm. High SERS activity hydrogel SERS chip for detection of traces of tebuconazole in wheat, peanut and corn. [Display omitted] •In situ in PVA solution of LSPR-tunable a-AgNPs were synthesized.•The hydrogel SERS chip could achieve remarkable EF as high as 9.58 × 108.•The hydrogel SERS chip showed impressive signal homogeneity and reproducibility.•Sensitive and quantitative detection of tebuconazole in wheat, corn and peanuts.