Method for the extraction and electrochemical detection of explosives and explosive components in soils using electrodes, filter paper, and electrolyte
Described herein is an approach using inexpensive, disposable chemical sensor probes that can be mounted on a small unmanned aerial vehicles (UAVs) and used to analyze a site (such as one known or suspected to contain explosive residue, spilled material or contaminated soil) without the need for a person to conduct ground operations at the site. The method involves contacting a soil or a surface with a filter paper wetted with a solvent, then subjecting the filter paper to voltammetry and/or spectroscopy, thus detecting a possible variation indicative of one or more analytes, wherein the solvent is selected from the group consisting of polar aprotic or protic solvents having a boiling point of at least 100° C., room temperature ionic liquids, and deep eutectic solvents.
1. A method of detection, comprising:
contacting a soil or a surface with a filter paper wetted with a solvent, then
subjecting the filter paper to voltammetry, thus detecting a possible variation in current indicative of one or more analytes,
wherein the solvent is the deep eutectic solvent consisting of a mixture of ethylene glycol and choline chloride.
2. The method of claim 1 , wherein said one or more analytes includes an explosive.
3. The method of claim 1 , wherein said one or more analytes includes a drug, nerve agent, biothreat, pesticide, or industrial pollutant.
4. The method of claim 1 , further comprising allowing migration of at least one of said one or more analytes across said filter paper prior to said subjecting to voltammetry.
5. The method of claim 1 , wherein said voltammetry comprises cyclic voltammetry using a copper-modified screen printed electrode and/or carbon electrode.
6. The method of claim 1 , wherein said contacting is performed by an unmanned aerial vehicle.