Ultrasensitive Quantification of Pesticide Contamination and Drift Using Silica Particles with Encapsulated DNA

Abstract

The rise of agricultural techniques with reduced pesticide usage makes it necessary to develop tools that efficiently assess pesticide drift at ultralow concentrations. We applied submicrometer sized silica particles with encapsulated DNA (SPED) as a tagging agent to evaluate pesticide drift. SPED have a quantification range down to the sub-parts per trillion level, allow cost-effective multiplexing experiments, and can be incorporated and robustly recovered from a wide range of pesticides and/or substrates. In a field experiment in an apple orchard, pesticide deposits down to 1 nL cm-2 could be quantified after spraying a SPED-labeled test liquid containing 5.8 ppm (milligrams per liter) SPED. Wind and field-related patterns were clearly traceable. Overall, SPED represent a suitable analysis tool for pesticide-related field evaluations.