An alternative to the time-consuming process of analyzing water samples in the laboratory to detect the environmental presence of pesticides is offered by use of portable sensors produced by additive manufacturing. Such as a 3D-printed sensor capable of detecting very low concentrations of pesticides in water has been developed by researchers from the University of Aveiro (Portugal), Leipzig University of Applied Sciences (Germany) and University of Glasgow (Scotland).

The device is based on surface-enhanced Raman scattering (SERS) technology to detect and identify trace amounts of molecules in test samples adsorbed on a metal surface by analyzing the unique ‘fingerprint’ of how the molecules scatter light. To design a SERS sensor with 3D-printed materials that adsorb moleculesThe 3D-printed sensor detects very low concentrations of pesticides in water. Source: University of Glasgow from water samples and deliver accurate initial results in the field, the researchers examined different types of cellular architectures composed of polypropylene and multi-walled carbon nanotubes.

The surface of the cellular structures produced using the fused filament fabrication 3D printing technique was coated with silver and gold nanoparticles using a common wet chemical approach to enable the SERS process. A lattice (periodic cellular design combined with silver nanoparticles proved the best material when tested with methylene blue dye and was then added to test strips to assay marine and freshwater samples spiked with low pesticide concentrations.

As reported in Macromolecular Materials and Engineering, the test strips detected molecules of the pesticides at concentrations as low as 1 micromolar — equivalent to one molecule of pesticide to a million molecules of water.