To feed the predicted world population of 9.7 billion people in 2050, it is required to raise the food production by ≈ 40 % between 2012 and 2050. To address this challenge, novel technologies such as remote monitoring of plant health is required. Moreover, the SARS CoV-2 pandemic demonstrated that we need rapidly adaptable sensing technologies to contain the spread of infectious diseases. Nanomaterial-based sensors are uniquely suited for such applications because nanomaterials possess tunable optoelectronic properties. Additionally, they can be chemically tailored for sensing by modifying them with (biological) recognition units. During the last few years, the field of nanosensors has seen tremendous progress and many novel functionalization techniques have been developed. While the large chemical space provides room for explorative work and optimization, it is challenging to sample it efficiently. In this context, rational approaches provide one mean for efficient functionalization. On the other side, high throughput approaches promise potential for analytes that are difficult to address with traditional recognition units such as antibodies e.g. to detect small molecules.