Optical sensor film for metribuzin pesticide detection

Sayed M Saleh; Fahad M Alminderej; Reham Ali; Osama I Abdallah

doi:10.1016/j.saa.2019.117971

Optical sensor film for metribuzin pesticide detection

Spectrochim Acta A Mol Biomol Spectrosc. 2020 Mar 15:229:117971. doi: 10.1016/j.saa.2019.117971. Epub 2019 Dec 28.

Authors

Sayed M Saleh¹, Fahad M Alminderej², Reham Ali³, Osama I Abdallah⁴

Affiliations

¹ Department of Chemistry, College of Science, Qassim University, Buraidah, Saudi Arabia; Chemistry Branch, Department of Science and Mathematics, Faculty of Petroleum and Mining Engineering, Suez University, 43721 Suez, Egypt. Electronic address: e.saleh@qu.edu.sa.
² Department of Chemistry, College of Science, Qassim University, Buraidah, Saudi Arabia.
³ Department of Chemistry, College of Science, Qassim University, Buraidah, Saudi Arabia; Chemistry Department, Faculty of Science, Suez University, 43518 Suez, Egypt.
⁴ Pesticide Residues and Environmental Pollution Department, Central Agricultural Pesticide Laboratory, Agriculture Research Center, Dokki, Giza 12618, Egypt.

PMID: 31954291
DOI: 10.1016/j.saa.2019.117971

Abstract

We present a new ratiometric and colorimetric optical sensor film for detection one of the most prevalent pesticide metribuzin. The detection proceeds within the low concentration range between 0 and 1.5 μM. The optical film is based on (a) near infrared (NIR) dye 2-[2-[2-Chloro-3-[2-[1,3-dihydro-3,3-dimethyl-1-(4-sulfobutyl)-2H-indol-2-ylidene]-ethylidene]-1-cyclopen-ten-1-yl]-eth-enyl]-3,3-di-methyl-1-(4-sulfobutyl)-3H-indolium hydroxide and (b) upconverting nanoparticles UCNPs of the NaYF₄:Yb,Er type (diameter ~40-100 nm) that can be emitted a dual (green and red) emission under 980 nm laser diode excitation. Commercially available polyvinyl chloride (PVC) was utilized as a homogeneous matrix for immobilizing NIR dye and UCNPs. The color of the NIR dye in the PVC matrix is based on the concentration of the metribuzin. When the sensor film is exposed to metribuzin the color changes from green to blue with a significant blue shift in the absorption peak (656 nm) of the NIR dye. Furthermore, the quenching of the red emission (659 nm) of the UCNPs is proceeded due to an inner filter effect. Thus, increasing the metribuzin concentration causes the red emission of UCNPs to be reduced. Conversely, the green emission (545 nm) of the UCNPs persists uninfluenced by metribuzin and can act as a reference signal. This optical sensor film provides great sensitivity based on their unique luminescence properties of UCNPs and recognition abilities within a very low detection limit for the metribuzin LOD 6.8 × 10^-8 M with a linear range of 0.23 to 1.5 μM and a relative standard deviation RSD_r (1%, n = 3). The novel optical sensor was applied to the detection of metribuzin in real water samples (surface and ground waters). The sensor film exhibits great selectivity in presence of different types of ions and pesticide molecules. But, atrazine pesticide interferes the analytical signal of the sensor film due to the presence of reactive amino groups in its structure. Memorably, we report the first optical chemical sensor film based on polymer film for metribuzin detection.

Keywords: Colorimetric; Inner filter effect; NIR dye; Ratiometric; UCNPs.