Overview
Our project was not only born in the lab, but rooted in the real world. Voices from the public, experts, and industry have all shaped our journey. These diverse perspectives pushed us to design a biosensor that is not only functional, but also accessible and socially responsible. Through Human Practices, we listen to the world—and make sure our voice is heard in return.
Exploring the Starting Point
Antimicrobial resistance (AMR) has become one of the most pressing global health challenges. The World Health Organization has repeatedly warned that unchecked resistance could undermine decades of medical progress. A recent Lancet study estimated that nearly 2 million people die each year directly from AMR, with millions more affected by related conditions, and by 2050 the majority of deaths will occur among the elderly.
The origin of our project lies in deep reflection on this issue: besides the well-known medical overuse of antibiotics, are there more concealed pathways of antibiotic exposure? Through extensive literature research, we found that the excessive use of antibiotics in animal husbandry is a severely underestimated source. Shocking data shows that about half of the total global production of antibiotics is used in animal husbandry, which is comparable to the amount used in human clinical treatment. In livestock farming, antibiotics are not only used to treat diseases but are often added to feed as growth promoters—this non-therapeutic use exacerbates the generation and spread of drug-resistant bacteria.
Farmer’s Voices on Antibiotics
Background
To gain a clearer picture of how antibiotics are actually used in livestock farming, we visited farmers and conducted interviews. Unlike data from papers or reports, these conversations allowed us to hear farmers’ voices directly and see how they approach antibiotic use in their daily practices. Our aim was not only to gather information, but also to understand the practical reasons behind antibiotic use and overuse.
Feedback
From the interviews, we found that small and medium-scale farmers often use antibiotics both for treatment and prevention, with dosages determined largely by experience and withdrawal periods rarely enforced. Many acknowledged that antibiotics reduce mortality, but few were aware of the long-term risks of resistance. For most, antibiotics were seen as essential tools for protecting income rather than as potential threats to public health.
As the discussions went deeper, it became clear that economics played the central role. Farmers believed antibiotics offered clear cost savings, while alternatives such as probiotics or herbal remedies were more expensive and less reliable under their conditions. Without strong market incentives or consumer premiums for “antibiotic-free” products, most farmers saw little reason to abandon antibiotics, making sustainable change difficult to achieve.
Figure 1: Interview with Farmer
Figure 2: Farm Environment Observation
Reflection
These interviews showed us that antibiotic misuse is not simply about a lack of awareness, but often a pragmatic choice shaped by economic pressure, limited options, and scarce information. For our project, this means highlighting scientific risks alone will not create change. A practical detection platform must be affordable, reliable, and easy to use if it is to be adopted at the grassroots level. This experience reminded us that advancing food safety requires not only technological solutions, but also empathy for and engagement with the people who are most directly involved.
Public Awareness of Antibiotics in Food
Background
As part of our preliminary research, we designed and distributed an online questionnaire to understand public awareness, attitudes, and needs regarding antibiotic residues in food. The survey helped us assess both the level of public concern and the potential value of our detection platform.
Feedback
The results showed that awareness exists but depth is lacking. Over 90% of respondents had heard of antimicrobial resistance, but only 17% claimed to “understand it well”. Nearly half mistakenly believed that growth-promoting antibiotics are still allowed in farming, and almost none could name official residue limits. While most were worried about residues in meat, followed by seafood, dairy, and eggs, very few had actually changed their purchasing behavior—revealing a clear gap between perceived risk and consumer action.
At the same time, consumers showed strong willingness to pay for safer food and practical testing. About 57% were willing to pay an extra ¥20 or more per month for antibiotic-free food, with families including children, pregnant women, or immunocompromised individuals showing the highest willingness. When asked about “10-minute in-store rapid testing,” 35% said they would definitely use it, 48% would decide depending on price, and only 17% said they did not need it. The most desired features were “easy for ordinary people, low cost, and testing multiple antibiotics at once,” reflecting demand for simple, affordable, and comprehensive detection tools.
Reflection
The survey revealed that the public is both anxious and expectant: they worry about residues but lack the knowledge and tools to act. For our project, this confirms the necessity and social relevance of developing a portable, low-cost antibiotic detection platform for the public. It also reminds us that technology alone is not enough—effective education and science communication will be essential for bringing such tools into everyday life.
Learning from Experts
To ensure our technical choices were scientifically sound and practically feasible, we consulted leading researchers and collaborated closely with fellow iGEM teams. Their insights helped refine our design and validate our direction.
Searching for Appropriate Base of Antibiotic Biosensor
Background
After defining our project needs, we considered which technology could achieve high-specificity and high-sensitivity detection of small molecules. Literature showed that enzymes, antibodies, and aptamers are widely used in biosensor design [1][2][3]. To determine the most suitable recognition element, we consulted Dr. Fang He from the State Key Laboratory of Chemo/Biosensing and Chemometrics at Hunan University.
Feedback
Dr. He highlighted the advantages of aptamers over antibodies and enzymes for small-molecule detection. Antibodies require animal immunization, are time-consuming and costly to produce, and often need additional modifications to bind small molecules, limiting their rapid application. Enzymes, though effective for some substrates, have narrow substrate ranges, are environmentally sensitive, and relatively costly, making them unsuitable for portable systems.
In contrast, aptamers can be obtained through in vitro SELEX, achieving high affinity and specificity. They are stable, easy to store and transport, and can be synthesized at low cost in bulk. Their programmable sequences allow integration with transcriptional amplification and fluorescence readouts, and swapping sequences enables detection of different targets—aligning with our modular platform design.
Figure 3: Comparison of Recognition Elements
Reflection
This consultation confirmed that aptamers meet both our scientific and practical requirements. Based on Dr. He’s advice and team discussions, we chose aptamers as the core recognition element of our detection platform.
Ask for advice on T7 transcription
Background
During the development of our double-strand displacement–transcription system, we encountered a significant problem: T7 promoter leakage. Even in the absence of the target molecule, transcription could still be unintentionally triggered, resulting in high background fluorescence.
To address this, our team aimed to design new structural architectures — such as a more radical single-strand sensor, in hopes of achieving tighter regulation. However, experimental progress at this stage was relatively slow.
Feedback
After consulting our mentor, we received valuable advice that helped us refocus our strategy. The mentor suggested that instead of developing entirely new frameworks, we could extend the 5′ end of the LBO strand within our existing design. This extension could complement and seal the T7 promoter sequence on the SRO strand, thereby preventing premature transcription.
Reflection and Improvement
Following this feedback, we redesigned and synthesized the modified sequences accordingly. The new constructions effectively reduced background leakage and improved overall system performance, validating our mentor's suggestion.
Reflection
This experience reminded us that sometimes, optimization within an existing design can be more efficient than reinventing the system entirely. The mentor's guidance not only accelerated our experimental progress but also helped us refine our design philosophy — emphasizing focused iteration and structural rationality in biosensor engineering.
Potential of CRISPR-Cas
Background
When T7 transcriptional amplification encountered challenges, we began exploring alternative strategies. We recognized that in the CRISPR-Cas12 system, activated Cas12 proteins exhibit trans-cleavage activity, allowing them to cut single-stranded DNA and thus serve as a potential signal amplification tool [4]. Initially, we planned to use the CRISPR-Cas12b system, and before detailed design, we consulted Dr. Pengfei Liu, a CRISPR-Cas expert at Hunan Normal University.
Feedback
Dr. Liu pointed out several limitations of Cas12b: it operates optimally at high temperatures (55–70 °C) and requires relatively long crRNAs (often over 100 nucleotides), making design and application more complex. These features reduce its suitability for portable detection. Instead, he suggested considering the CRISPR-Cas12a system, which is more widely used, more mature, and easier to design. He further advised that when designing Cas12a crRNAs, the target length should be appropriate and adding flanking bases around the target sequence could improve recognition efficiency.
Reflection
After this discussion, we confirmed that Cas12a functions well at moderate temperatures (37 °C) and uses shorter, simpler crRNAs [5]. These properties make it more suitable for our detection platform. Based on Dr. Liu’s advice and our evaluation, we ultimately selected the CRISPR-Cas12a system for signal amplification.
Collaboration and Growth Across Teams
Background
As our project progressed, we regularly held joint group meetings with another team from our university, HNU-China, to discuss experimental progress and listen to their suggestions. We found that the differences between the two teams’ projects provided valuable inspiration, and working together continuously strengthened our motivation and confidence in research.
Feedback
During these discussions, we not only ensured that our own team members clearly understood the project but also provided HNU-China with as much detail as possible. This process, in turn, deepened our own understanding of the experiments. The PIs from HNU-China also offered valuable advice. For example, Professor Songqing Tang suggested that beyond detecting antibiotic targets in simple solutions, we should also evaluate the influence of complex matrices—such as testing our system’s anti-interference performance in simulated plasma—to better approximate real-world application conditions.
Figure 4: Joint Meeting with HNU-China
Figure 5: Collaborative Experiment Design
Reflection
Our interactions with HNU-China highlighted the value of inter-team collaboration. Sharing experimental ideas and feedback not only improved our grasp of the project but also broadened our perspective on its potential applications. This cross-team cooperation helped us identify new directions for improvement and reinforced core values of openness, collaboration, and collective progress.
From Lab to Application: Industry Visit
Background
In our project exploration, we not only focused on testing biosensors in the laboratory but also considered their potential for real-world applications. To this end, we visited and communicated with Sinocare Inc., a company specializing in biosensors for glucose and uric acid detection. This visit provided valuable guidance for the practical application of our sensor system.
Feedback
By studying the detection technologies used in the company, we learned that although the detection targets are different, the fundamental logic of biosensors remains consistent: a recognition module + a signal transduction module. The company’s model is “enzyme recognition + electrochemical signal,” while our project is “aptamer recognition + transcriptional fluorescence amplification.” This modular concept helped us realize that biosensors share a universal design framework, which can be adapted and extended to different application scenarios.
Through conversations with engineers from the test strip R&D department, we also understood that product evaluation is not limited to sensitivity alone. Accuracy determines the credibility of the results; stability and reproducibility ensure consistency across batches and under different conditions; and the linear detection range guarantees reliable responses across varying concentrations. These criteria, often overlooked during academic exploration, are in fact crucial for commercialization. This realization clarified the future optimization directions for our project: beyond pursuing signal strength and specificity, we must also gradually consider stability and practical applicability.
We were also deeply impressed by the portable testing model of glucose meters. This technology has already been widely applied in clinical diagnostics and home health monitoring, demonstrating the maturity of biosensors in real-world use. The company’s practice showed us that a truly user-friendly detection kit usually requires the integration of several elements: a recognition unit, a signal amplification unit, a readout unit, and a portable interface. Comparing this with our own design, we realized that our aptamer recognition, transcriptional amplification, and fluorescence readout should ultimately be integrated into a portable, low-cost, and user-friendly platform. This provided a clear reference for envisioning a food safety detection kit and further encouraged us to consider the engineering pathway for our system.
Figure 6: Sinocare Portable Glucose Meter
Figure 7: Team Touring R&D Lab
Figure 8: Discussion with Engineers
Reflection
The industry visit gave us a clearer understanding that our project should not remain confined to laboratory validation but should progressively align with real-world needs and applications. Scientific research is not only about exploration but also about responsibility—providing safe, reliable, and accessible solutions for the public. In the future, we plan to develop a food safety detection kit that allows users to complete testing with simple operations. Through this effort, we hope to transform the outcomes of synthetic biology from academic exploration into practical applications, respond to societal concerns, and ensure that technology benefits a wider community.
Public Engagement
Beyond expert consultations and field research, we actively engaged with students and the broader public to bridge the gap between science and society. Their input profoundly influenced our design philosophy and outreach strategy.
Dialogue with Future Executors
Background
The sustainable development of our team relies not only on current research achievements but also on attracting and nurturing future potential members. To this end, after the freshmen joined the university, we organized a laboratory open day. During the event, we guided the freshmen through our lab, introduced them to the iGEM competition, our research direction, and the ongoing aptamer-based biosensor project. We hoped that this activity would allow the students to experience the charm of synthetic biology firsthand, while encouraging them to think from the perspective of “future project executors”: if they were in charge of this project, what aspects would they pay the most attention to?
Feedback
The freshmen showed great interest. They not only raised scientific questions about the project, such as “Can aptamer detection be applied to other molecules?” and “Will the T7 transcription and CRISPR-Cas amplification modules interfere with each other?”, but also pointed out concerns from the perspective of end-users and practitioners, such as “If this technology is to be promoted to society, can it be made simple to operate?” and “Will the detection results be sufficiently stable and reliable?”
These questions helped us break out of the limitations of a researcher-centric mindset and recognize areas for improvement in our project. For example, the freshmen’ concerns reminded us of the importance of testing against structurally similar interfering substances, in order to evaluate whether our system possesses sufficient specificity.
Figure 9: Lab Tour for Freshmen
Figure 10: Student Interaction Session
Reflection
Through this lab open day, we realized that the questions raised by the public and new members are themselves a form of reverse driving force: they helped us reflect on the shortcomings of our project in terms of feasibility, usability, and educational value. At the same time, this activity not only nurtured the scientific curiosity of the freshmen but also laid a foundation for team continuity and future development. Looking ahead, we plan to institutionalize such lab tours, allowing more students to experience synthetic biology up close, learn about our team’s research, and be inspired to become future iGEMers.
Public Survey: Food Safety and Future Detection
Content
One of the key features of our detection platform is its modularity and interchangeability: by altering the aptamer sequence, the platform can be adapted to detect different targets. With this in mind, we chose the Mid-Autumn Festival, a time of high public participation, to conduct a food safety outreach survey. Through this event, we aimed to understand the broader public concerns and questions regarding food safety beyond antibiotic residues, in order to identify potential future targets for our detection platform.
Feedback
In the interviews, the public expressed multifaceted concerns about food safety. Some participants focused primarily on antibiotic residues in meat and dairy products, while others raised concerns about pesticides and food additives. These insights revealed that the public’s understanding of “food safety” is broad, and antibiotic residues represent only one aspect of it. Moreover, people consistently emphasized the need for detection methods that are simple, rapid, and low-cost, making them accessible for everyday use. This feedback reinforced the necessity of developing a portable detection platform and reminded us to carefully consider usability and user experience in our design.
Figure 11: Mid-Autumn Festival Outreach Booth
Figure 12: Community Members Participating in Survey
Reflection
This public engagement activity gave us a deeper appreciation that scientific research must not be isolated from its social context. Public concerns about food safety not only provided us with valuable inspiration but also reminded us of our responsibility as a research team: to bring science out of the laboratory and respond to real-world challenges. Through face-to-face dialogue, we gained a crucial “user perspective” that will help us optimize our sensor design to better serve people’s daily lives. This experience also strengthened our commitment to the values of scientific responsibility, public engagement, and open sharing, and reinforced our determination to transform our project outcomes into tangible social value.
References
- Sevinc Kurbanoglu, Cem Erkmen, Bengi Uslu. Frontiers in electrochemical enzyme based biosensors for food and drug analysis. Trends in Analytical Chemistry 124, 115809 (2020).
- Victor Crivianu-Gaita, Michael Thompson. Aptamers, antibody scFv, and antibody Fab' fragments: An overview and comparison of three of the most versatile biosensor biorecognition elements. Biosensors and Bioelectronics 85, 32–45 (2016).
- Lucy F. Yang, Melissa Ling, Nataly Kacherovskya, Suzie H. Pun. Aptamers 101: aptamer discovery and in vitro applications in biosensors and separations. Chemical Science 19 (2023).
- Janice S. Chen et al. CRISPR-Cas12a target binding unleashes indiscriminate single-stranded DNase activity. Science 360, 436–439 (2018).
- Rananaware S.R., Vesco E.K., Shoemaker G.M., Anekar S.S., Sandoval L.S.W., Meister K.S., Macaluso N.C., Nguyen L.T., Jain P.K. Programmable RNA detection with CRISPR-Cas12a. Nature Communications 14, 5409 (2023).
