Biosensor based on a peptide represents an advance in the detention of copper ions present in coffee plants. Newly-developed by scientists from Embrapa Genetic Resources and Biotechnology (Brasília, DF), the innovative technology will enable the development of portable systems to detect the metal in plants, which today is only possible through laboratory analyses. In addition to applications in detecting environmental and plant contamination, the biosensor can also be used to determine the geographic origin of coffee. Metal ions are already being used as markers to identify the origin of products such as wine and coffee, reports the researcher Marcelo Porto Bemquerer, one of the scientists responsible for the technology. “Brazil is the largest producer and second largest consumer of coffee, which makes the characterization of the quality and of the production origin of the bean essential”, the scientist observes. The copper found in coffee mainly comes from copper fertilizers and from some agrochemicals used in the crop. In given concentrations, it can be toxic and cause physiological changes to the plant. In Brazil metal ions are more commonly detected in the water and the soil. There are low-cost and efficient methods to determine copper in the soil and respective consequent bioavailability for the plant, however, they are not easily applicable in the field because they are recorded in large-sized equipment. In the case of the biosensor, however, it is possible to make the analysis in the plantation itself, if a portable potentiostat and printed electrodes are used . This research stage is still in progress. Several studies point that metal nanoparticles can release metal ions that contribute to toxicity in plant tissue. “The application of the copper biosensor in the scope of nanotoxicology is important. This modern area of investigation has strongly contributed to the environment and agriculture. Moreover, human toxicity must not be neglected”, states the Embrapa researcher Clarissa Pires de Castro, who also participated in the development of the technology. How it works To test the biosensor application, the analyst Gabriela Magarelli developed selective copper determination methods for application on coffee plant seeds and fruits that had been submitted to copper fertilizer treatments. The samples will be compared to other fertilizer-free ones. At this stage of research, which is ongoing, it is necessary to determine method validation parameters such as detection limits, precision and method selectivity. Coffee trees are susceptible to diseases caused by fungi, which significantly reduce plant yield. Growers normally spray the crop with copper based fungicides to prevent the problem, which entails a palliative solution that causes negative impacts in the environment, crop costs, and health. Environmentally cleaner From an environmental standpoint, the biosensor is one of the technologies that contributes to reducing the use of reagents in electrochemical analyses, as opposed to conventional methods. Products that are selected based on the device should have greater added value, due to the proof and certification of their nutritionais properties and absence of toxic metal ion levels above of the limits allowed. The results obtained in the validation tests demonstrate that the technology should influence and cover all Brazilian coffee producing regions, and could be used by farmers, research institutions, universities, consumer protection agencies, and to produce data for the chemical characterization of different coffee species. The research led by Embrapa Genetic Resources and Biotechnology was initiated in 2015 and will be concluded in the second half of this year, involving scientists from three other Units of the corporation (Embrapa Coffee, Embrapa Cerrados, and Embrapa Instrumentation) and from the University of Brasilia (UnB). The project is part of the Agronano Array, led by Embrapa Instrumentation (São Carlos, SP). Translation: Mariana Medeiros.