A label-free diffraction-based sensing displacement immunosensor toquantify low molecular weight organic compounds

Abstract

[EN] Herein we present a diffractometric immunosensor to quantify low molecular weight organic compounds in a label-free, simple, and sensitive fashion. The approach is based on patterning analyte analogues (haptens) on solid surfaces according to a diffractive structure, and then loading specific antibodies on them to be subsequently displaced by free analytes in solution. This displacement generates a measurable change in the diffractive response that enables to quantify the analyte concentration. In this study we address the fabrication, optimization, and assessment of these diffractive structures of biological probes and their application to the analysis of atrazine, an organic compound extensively used as pesticide. This immunosensor displays well-correlated dose-response curves that reach a detection limit of 1.1¿ng¿mL¿1 of atrazine in label-free conditions. From a general viewpoint, this study also aims to provide insights into exploiting this approach towards prospective in-field analysis and screening strategies to sense multiple low molecular weight compounds in label-free conditions.This work was supported by the Spanish Ministry of Economy and Competitiveness (CTQ2013-45875-R and FIS2011-23175), FEDER, and the Generalitat Valenciana (PROMETEO II/2014/040 and PROMETEO II/2014/072). Special thanks go to Richard A. McAloney and M. Cynthia Goh for hosting M.A.-O. as visiting researcher, sharing their expertise, and offering their valuable support. M.A.-O. also acknowledges the FPI program of the Spanish Ministry of Economy and Competitiveness for a PhD and an EEBB mobility grant.Avella-Oliver, M.; Ferrando Martín, V.; Monsoriu Serra, JA.; Puchades, R.; Maquieira Catala, A. (2018). A label-free diffraction-based sensing displacement immunosensor toquantify low molecular weight organic compounds. Analytica Chimica Acta. 1033:173-179. https://doi.org/10.1016/j.aca.2018.05.060S173179103