Experts in spectroscopy
The measuring method used in the Rambox system is based on Surface-Enhanced Raman Spectroscopy (SERS). We use this method to detect low concentrations of substances in agricultural products due to its excellent chemical selectivity allowing to distinguish the signal of the substance from the background signal of the agricultural product, as well as high sensitivity of measurement, allowing to achieve the required detection limit specified in the standards.
The SERS effect enables gigantic enhancement of the weak Raman scattering intensity through the presence of a nanostructured metallic surface, the so-called substrate. In general, the SERS gain value is around 106, but can reach as high as 1014 under certain conditions. The use of the SERS technique not only improves the overall surface sensitivity, but also makes Raman spectroscopy one of the alternative analytical techniques.
Silver (Ag), gold (Au) and copper (Cu) nanoparticles are usually used as the active SERS substrate. These substrates can be roughly divided into three categories:
- metal nanoparticles (MNP) in suspension,
- metal nanoparticles immobilized on solid substrates,
- metal nanostructures produced directly on solid substrates by nanolithography and template-based synthesis.
Qualitative and quantitative measurements
In Raman spectroscopy, the test sample is illuminated with laser radiation, and then the radiation generated as a result of inelastic scattering of optical radiation in the tested object is recorded. As a result of Raman dispersion, so-called Stokes and anti-Stokes waves are generated, which frequencies are respectively: the difference and the sum of the laser wave frequencies and the chemical bond vibration of the molecule under study. In practice, only the Stokes wave is recorded, due to the higher intensity of the measuring signal. The difference in bond vibration and excitation wave is specific to a given chemical bond. For this reason, the system of many chemical bonds present in the tested substance is its unique standard. Thanks to this, qualitative analysis is possible, i.e. recognition of the chemical composition of the tested sample consisting of a mixture of many substances. Since the signal strength is proportional to the number of molecules of the substance in the illuminated volume, it is possible to make quantitative measurements that allow determining the concentration of the substance.
Rambox measuring process
Performing a Rambox test are just a few simple steps. The user’s participation is limited to placing the agricultural product sample in the device (1) and reading the measurement result (5). The device itself processes the sample to the form required for measurement (2), then measures the Raman spectrum (3), analyzes the measurement signal using artificial intelligence algorithms (4) and presents the result of the measurement (5) determining whether pesticides are present in the sample and what is their concentration.
Advantages of Rambox technology
- Own concept, design and production of SERS substrates, optimized for pesticide measurements in selected agricultural products.
- Mobile test device for monitoring pesticide levels at the place of production (in the field, in the orchard, etc.).
- Operator does not need to be a qualified chemist or technician to operate it.
- Low cost of single test (critical factor for screening).
- Very quick measurement process (minutes) with high chemical specificity and measurement sensitivity.