A biosensor platform for soil management: the case of nitrites

Conventional farming faces unprecedented pressures and challenges related to climate change, resources constraints, and food security. Cleaner production involves environmental-friendly and knowledge-based agricultural practices that extend natural recycling and minimize the input of chemicals. Precision agriculture and site-specific management drive a new era in farming technology based on the direct measurement of soil properties on-the-go. Although a variety of sensing technologies have been proposed for a variety of chemical compounds, the use of different technologies, each with its own protocol of measurement, operating requirements, and handling expertise, to span one field might fail to support decision making. The idea, on the other hand, of employing a common detection platform, readily modified and adjusted to assess different species as needed, might turn into a key concept in soil management. Towards that end, this paper reports on a versatile lipid nano-platform that allows the easy customization of sensor's selectivity and sensitivity through the adjustment of macro-parameters. As a pertinent case example, the development of a soil nitrite biosensor is presented, including a detailed design rationale, optimization of the chemical and physical variables, and the preliminary validation results on simulated soil and real soil samples. The sensor exhibits high tolerance to interfering ions, a detection limit of 2.1 μg/L for soil extracts and a lowest detectable field nitrite ion concentration of 1 ppm.