The Inspiration

Nestled in the heart of the enchanting island of Crete, Greece, our team draws its inspiration from the rich tradition of olive cultivation that has flourished here for generations. As proud residents of our community, we intimately understand the challenges faced by local farmers. Guided by the ethos “Local Problems solved by Local People” , we set forth on a journey propelled by scientific expertise and creativity, resulting in the birth of DeltaSense.
To provide a statistical backdrop on Crete's agricultural heritage, the Greek Statistical Authority (ELSTAT) reports that in 2021, Crete boasted an impressive 38,134,039 olive trees, producing 985 tons of edible olives and a substantial 616,370 tons of olive oil. There are approximately 98,000 agricultural enterprises, with expansive olive groves covering 160,000 acres, representing 65% of Crete's total agricultural land and employing nearly half of the Cretan workforce. These figures underscore the olive grove’s dominating role in Crete’s agricultural legacy.

The Challenge

As a team deeply connected to our ocal community and environment, we face a significant task. It's driven by our genuine concern for the well-being of our neighbors and the sensitive ecological harmony that sustains us. This mission embodies our shared belief in finding a solution that not only protects our environment but also enriches the lives of those we hold dear. Thus, after long-lasting yet creative brainstorming, we decided to confront the local matter of pesticide overuse targeting deltamethrin.

Why pesticides?

Despite Greece's and specifically Crete's reputation for effective agricultural practices, the unregulated use of pesticides has emerged as a significant concern. Driven by the desire to increase productivity, reduce labor costs, and maximize profits, this practice has escalated due to limited awareness of pesticide risks.
Furthermore, insufficient training and the rising price of olive oil have exacerbated the problem, leading to heightened pesticide use. The increasing demands of a growing population for food and agricultural products also contribute to this trend.
Since the 1990s, agriculture has placed greater pressure on the environment. Recent data from the Ministry of Environment and Energy reveals that 3,230 tons of pesticides are used annually in Crete, with a staggering 9,384 tons nationwide. This translates to 2.9 kilograms of pesticides per hectare of cropland, ranking Greece as the sixth-highest consumer of pesticides among EU nations in 2021.
While pesticides play a crucial role in pest control and yield enhancement, their potential to migrate after application introduces various negative aspects when used indiscriminately. This underscores the need for greater caution and regulation in their application.


Pesticides enter the environment through various means, including manufacturing plants, mixing and loading facilities, accidental spills, wastewater recharge sites, waste disposal areas, sewage treatment plants, runoff from agricultural and urban areas, seepage in regions where pesticides are used, and atmospheric deposition. These sources contribute to the presence of pesticides in streams and groundwater.
Following their introduction into the atmosphere, streams, or groundwater, the dispersion of pesticides and their degradates (formed through chemical or biological processes) is influenced by their inherent chemical and physical attributes. Their transportation can transpire through air, water, or particles.


Why especially deltamethrin?

Widely utilized in Greek olive groves, particularly in Crete, deltamethrin has garnered attention due to its high toxicity among pyrethroids. The Greek Ministry of Agricultural Development and Food reports that out of 70 formulations used to combat the olive fruit fly, 49 contain deltamethrin, slated for approval withdrawal by October 31, 2024. Such announcements emphasize the necessity for regulated application , especially in light of the food safety industry's efforts to advance techniques for detecting pyrethroid residue in both crops and water samples.
Deltamethrin is a prevalent choice for controlling the olive oil fruit fly (Bactrocera oleae), notorious for its impact on olive pulp and oil quality. This pest specifically leads to early olive dropping, necessitating frequent spraying for consistent production. Type II pyrethroids, like deltamethrin, initiate a sequence of repetitive nerve signals in the fly's sensory organs, nerves, and muscles. However, its overuse could adversely affect various non-target species , like honey bees, fishes and even if temporarily, harm animals’ nervous systems.
Given the characterization of deltamethrin’s properties highly unsuitable for the European Market and the contrasting preference it enjoys among Cretan olive producers, we have opted to address this challenging issue and assist in its detection. Moreover, the sense of responsibility and interest in biodiversity that drove us to participate in the competition could not but be demonstrated concretely through the choice of our project.

Our solution

Despite recent bans on certain harmful pesticide substances, their continued use in Europe poses significant environmental and health risks. Recognizing the need for proactive solutions, we are developing a highly sensitive and specific biosensor for deltamethrin detection. This biosensor leverages strong aptamer-ligand binding to enhance selectivity and sensitivity. Our ultimate aim is to create a user-friendly aptamer biosensor capable of swiftly identifying deltamethrin in water samples, especially if levels exceed EU-set limits based on the sample's source. Furthermore, with adaptations, this versatile system can be repurposed to detect various target molecules by altering the aptamer sequence.

Why aptamers?

Aptamers are short, synthetic single-stranded oligonucleotides (DNA or RNA) that can bind to target molecules with high affinity and specificity towards a diverse spectrum of target molecules, spanning from chemical compounds to complete cellular entities. The reason why we focused on the use of aptamers is mainly the multitude of positive features they display.
First, the ability of the aptamer to specifically bind to target molecules, followed by controlled release, endows the aptamer with excellent reusability, so that in our experiments we could use different concentrations of deltamethrin without changing its utility. In addition, their easy maintenance and the simplicity they offer allows the construction of portable sensors as well as on-site or point-of-care (POC) detection. Compared with proteins (or antibodies) used in the immunological analysis, nucleic acids possess a feature that could be easily amplified via various approaches. Besides, aptamers have a longer shelf life, improved thermal stability, and could be modified and conjugated more easily, which enable them to become a powerful tool in biochemical analysis. Lastly, the progressive integration of aptamers into the domain of biosensors highlights the importance of our research efforts in discovering an aptamer that selectively binds to deltamethrin, as no such aptamer is extant in the current scientific literature.

Aiswarya P. U, (2023), Aptamers: Features, Synthesis and Applications

Why cell-free?

The use of biosensors for detecting various molecules, viruses, harmful metals, and other substances is increasingly common and has captured substantial attention within the scientific community. Constructing cell-free biosensors, despite the challenges they pose, offers several advantages. Notably, these biosensors provide a flexible and straightforward detection system. They can detect various molecular and chemical targets, all while being easier to manufacture and use since living cells are not involved.
Additionally, cell-free biosensors promise faster response times and greater portability. Regarding the response time, the absence of cellular metabolism allows for quicker outcomes, relying on various mediated chemical reactions. Moreover, when living cells are absent, the need for specific conditions to sustain them is eliminated, enabling greater portability. The longevity of the sensor is also extended, reducing risks and creating opportunities for future enhancements or integration with other technologies. Cell-free biosensors often demonstrate robustness and resilience, enabling them to endure harsh storage conditions and possess longer lifespans compared to their living cell counterparts. This stability proves advantageous for commercial production, distribution, and use across various environments.
Furthermore, the utilization of cell-free biosensors alleviates ethical concerns associated with living cells, such as the need for cell culture maintenance, potential genetic modifications, and the use of animal models. In addition, these biosensors can be easily integrated with other technologies, such as nanomaterials or electronic readout systems, enhancing their capabilities and facilitating miniaturization, increased sensitivity, and real-time monitoring.

Our Vision

Team uniCRETE is committed to developing innovative solutions for environmental challenges. Our core focus is on creating a user-friendly biosensor to detect deltamethrin levels in water samples, ensuring compliance with EU standards. This technology holds potential for broader applications in environmental contaminants detection in liquid samples. Our goal is to provide a versatile tool that addresses current issues, through constant enhancement of our biosensor technology, while paving the way for a more sustainable future.
Moreover, we're enthusiastic about teaming up with environmental agencies and respected laboratories in pursuit of upgrading our system proposal. Partnering with these crucial allies will bolster our endeavors and hasten the global adoption of our cell-free aptamer biosensor technology. Together, we're set on igniting a change in environmental monitoring, pushing towards a world where preserving our ecosystems is everyone's mission.

References

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