Rapid on-site detection of paraquat in biologic fluids by iodide-facilitated pinhole shell-isolated nanoparticle-enhanced Raman spectroscopy

Abstract

An on-site direct detection method for paraquat in biologic fluids was developed on the basis of iodide-facilitated pinhole shell-isolated nanoparticle-enhanced Raman spectroscopy. A full removal of matrix interference on the nanoparticle surface from the complicated biologic samples, and a selective attraction of paraquat to “hotspot” via a highly electrostatic adsorption on the iodide-modified nanoparticle surface are accomplished in this method. Four distinguished characteristics were provided as (1) high sensitivity with a limit of detection of 1 μg L⁻¹ for paraquat; (2) free of pretreatment with a direct measurement in plasma or urine finished within 1 minute; (3) on-site detection using a portable Raman spectrometer; and (4) high antifouling stability during measurement with the pinhole shell-isolated nanoparticle structure. This method was further showed its great clinical diagnosis applicability on a rapid, accurate detection of the plasma and urine samples from a paraquat poisoned patient.