Foodborne disease is a serious global issue. According to the World Health Organization (WHO), approximately 115 million people are infected with Salmonella each year, resulting in about 370,000 deaths (World Health Organization, 2018). Specifically, Salmonella causes around 95 million cases of gastroenteritis, leading to over 50,000 fatalities (World Health Organization, 2018). The rising trend of foodborne bacterial infections is evident in China as well. Li (2023) reported that over 20,000 cases of foodborne bacterial infections occurred in households, accounting for 50% of the total foodborne infections in the country. These data underscore the necessity for efficient, accurate, and reliable methods to detect foodborne bacteria.

To address this issue, team members from across China gathered in Shanghai to form this iGEM team, aiming to explore new methods for detecting foodborne bacteria. Our goal is to establish a new colourimetric biosensor, AuNPs@PBP, integrated with monochromatic infrared energy, for the direct detection and subsequent inactivation of foodborne pathogens, including Escherichia coli, Salmonella, and Staphylococcus aureus. This approach is expected to replace traditional bacterial detection methods. The detection results will be displayed on a mobile phone app, allowing for the rapid detection of foodborne bacteria in a short period.

In conclusion, we expect our topic to positively impact society by reducing the number of infections and preventing the spread of foodborne bacteria. Our integrated human practices involve continuous reflection and improvement of our topic based on feedback from various stakeholders.

Survey 1: Public Awareness of Foodborne Bacteria Infection

Nowadays, people pay more attention to food safety. This survey aims to understand public awareness, develop more effective promotion and education strategies, and improve social responsibility and credibility. In developing new therapeutic drugs, the opinions and needs of the public are considered, reflecting the project's social responsibility. This helps to enhance the project's credibility and win more social support and recognition.

Generally, we decided to use questionnaires to help us complete the investigation. 264 people answered our questionnaire. Most of them (119, taking 45.08%) were between 16-24 years old. Followed by under 16 years old and 25 to 35, which is 19.7% and 16.29% respectively. 13.64% of the sample were between 36-45 years old. People aged above 46 make up 5.31% (figure 2).

According to Figure 3, only 2.27% of people are very aware of foodborne bacterial infections. The majority, 53.41%, have some understanding of foodborne bacteria. However, a significant proportion, 29.17%, have no knowledge about foodborne bacterial infections. This indicates that overall, people are not very familiar with foodborne bacterial infections.

Up to 80.68% of people believe that Salmonella can cause foodborne bacterial infections, while 67.8% believe that Staphylococcus aureus can cause the same. In comparison, only 32.58% of people recognize that Vibrio parahaemolyticus can cause foodborne bacterial infections, despite its capability to do so.

Furthermore, more than half of the respondents believe that Aspergillus can cause foodborne bacterial infections, with 42.05% thinking the same of Candida albicans. However, neither of these can cause foodborne bacterial infections. Aspergillus is a fungus, not a bacterium (Xu, 2021). Similarly, Candida albicans is a common fungus and a probiotic that helps maintain the normal balance of human microbiota. Normally, food is cooked at high temperatures or stored for a certain period, causing fungi to lose their activity or be killed. Therefore, a typical diet does not lead to Candida albicans infection (Ding, 2024). It indicates that people's awareness of foodborne bacterial infections is limited, and they may not even distinguish between bacteria and fungi. Thus, there is a need to strengthen education on this topic.

Additionally, over half of the respondents selected 'Isolate infected patients' in response to the question 'What are effective measures to prevent foodborne bacterial infection'. However, this is incorrect, as Huang (2015) indicates that the primary methods to prevent foodborne bacterial infections do not include isolating affected patients. This suggests that respondents may have confused foodborne bacterial infections with intestinal bacterial infections. These findings highlight the public's lack of knowledge about foodborne bacterial infections, underscoring the need for more educational activities to disseminate accurate information on this topic.

These given graphs illustrate a pattern that people have already had some basic understanding on food safety and took several actions to avoid the spread of foodborne bacteria. Figure 6 shows that the majority of people have the awareness to differentiate the cutting of raw meat and vegetables, which significantly exceeds the percentage (37.88%) of people who don’t take any action. In Figure 7, the maximum frequency that can be seen from the graph is to clean the kitchen on a weekly basis (40% people), followed by daily and monthly (27.65% and 19.32% respectively). The number of people who rarely or never notice their kitchen tidiness fluctuated at a very low percentage. Figure 8 peaks at 56.82%, which means half of the people always check the expiration date, and over 90% of people check the expiration date frequently.

Overall, we can see that the prevention of foodborne bacteria has already penetrated in people’s daily life like checking the expiration date before ingestions, cleaning kitchen and changing cutters when treating raw food. This means that it is very promising for us to create a product that can promote food safety due to people’s rising awareness and also possible for people to cultivate a living habit related to using food safety detection device, which greatly enlarge the demands for our product.

The diagram 9 and 10 shows that more than 50% of people prefer to participate in activities exclusively online, making this the most favored format. About 36% of people are willing to engage in both online and offline activities, a significant number but still lower than the preference for online-only participation. The third option, with 10.23% of respondents, is not wanting to attend any educational program, regardless of the format. Lastly, only about 2.27% of people prefer solely offline activities, a much smaller percentage compared to the other options. The data suggests that online-only activities are the most favored and acceptable. Therefore, when developing educational programs, we should consider focusing on online activities.

Regarding online platforms for learning about food-borne bacterial infections, more than 50% of people prefer using Little Red Book, Bilibili, or TikTok. Little Red Book is slightly more favored at 56.82%, followed closely by Bilibili at 53.41%. Baidu and WeChat video accounts are also popular, with each being preferred by around 34-35% of respondents. Weibo ranks lower, with 20% of people favoring it. The least favored platforms are Kuaishou, Tieba, and others, with Tieba being the least popular at 9.09%. Based on this data, we created several social media accounts, such as in Little Red Book and online blog, to impart the knowledge of synthetic biology and the issue of foodborne bacterial infection.

In conclusion, this survey indicates that food safety has become an increasingly important issue in people's daily lives. To protect their families and themselves from foodborne bacteria, more consumers are taking effective precautions. They pay attention not only to expiration dates when buying food but also to maintaining a clean kitchen and using different cutting boards for raw food to prevent cross-contamination. This trend presents a significant market opportunity for promoting food safety products. Our products not only help consumers better manage and maintain their food safety but also integrate seamlessly with existing lifestyle habits and preventive measures. By providing advanced food safety testing equipment, we are committed to creating an environment where consumers can buy and use food with confidence and peace of mind.

Meanwhile, the questionnaire survey also provided more constructive suggestions for our Education and BP part. There are many people who have misconceptions about foodborne bacteria, such as many respondents believe that "isolating infected individuals" can prevent foodborne bacteria. We will carry out educational activities to spread accurate information about this topic. We also learned from the questionnaire that many people are still very concerned about their own health and the detection of foodborne bacteria. Therefore, we will strive to develop related products to help more people detect foodborne bacteria in their daily lives.

Survey 2: Public Demands and Needs of an Innovative Detection Method

Our team conducted another survey to understand the public's needs and expectations regarding bacterial detection methods. We administered the survey online, which provided clear insights into how we can improve our product.

Our survey sample consisted primarily of individuals under 60 years old (192 respondents, or 96%), who represent our target customers. Additionally, 97% of respondents expressed awareness of food safety, indicating a high potential acceptance of our project. Moreover, over half of the respondents expressed a need for a device that can quickly detect bacteria and indicated their willingness to try our product.

Moreover, according to the survey, most people would like to use our product when cooking for individuals with low resistance, such as the elderly and children. They also expressed interest in using the product when they suspect their food might be contaminated. Approximately half of the respondents prefer a straightforward indication system, such as red for dangerous and green for safe.

We have also identified ways to improve our product in the future. According to our findings (figure 14), 84.5% of respondents want a faster detection method. Although our product is quicker than ELISA or PCR, there is still room for improvement. Additionally, 84% of people want the product to be more convenient to use, so we will work on making it more user-friendly. Furthermore, while some people are willing to accept a higher price for better performance, about 60% hope the cost can be reduced to under 500 yuan (figure 16). Therefore, we will strive to reduce costs as much as possible in the future.

More than 10 people participated in this public focus group interview. The participants included housewives, professionals in the food industry, and health-conscious consumers. However, the majority were migrant workers and students working in rural and urban cities.

This interview had multiple diverse purposes. Firstly, we aimed to gain a deeper understanding of consumers' interests, needs, and expectations for fast bacterial detection devices that can be used in conjunction with smartphones. Secondly, we sought to explore the market adaptability and user acceptance of our developed equipment for detecting foodborne bacteria. Additionally, collecting user feedback and suggestions for improvement was a significant objective of our integrated human practices.

During this online interview, we gathered a large amount of information. The participants demonstrated a high awareness of food safety, with many having heard about or experienced foodborne bacterial infections. One interviewee mentioned, "Foodborne bacterial infection is relatively common, so I think I am willing to buy them." Despite receiving positive recognition from potential customers, we also received numerous effective suggestions for our products.

Regarding the product's color, size, and appearance, a young woman (an educator) and a middle-aged man suggested that the product should be compact, convenient, and not overly fancy. In terms of usage frequency, participants indicated a preference for using the product before consuming takeout food and overnight leftovers. For practicality, the consensus was that if the test time is around five minutes and the accuracy is high, the product would be considered very practical.

Concerning the integration with smartphones, some participants (students) found it very convenient. However, others pointed out that smartphones might not be user-friendly for the elderly, who are a primary target group for this product. Therefore, we decided to design an elderly-friendly version that displays the test results directly on the packaging box.

In terms of pricing, most participants were willing to pay hundreds of dollars, though students preferred their parents to purchase it for them. This suggests that our potential end users are adults with the economic capacity to afford the product. Additionally, participants indicated a willingness to spend more money on more efficient products, so we should focus on promoting advanced products.

Finally, the suggestions for improvement included reducing the test time, clearly indicating whether the food is safe to eat, and ensuring higher accuracy. In conclusion, the feedback received from the participants was very useful and valuable, and we will continue to improve our products to meet customer requirements to the greatest extent.

We recognize the importance of expert advice, so we interviewed Professor Qin Zhen, a food enzymology expert from Shanghai University who has contributed 13 sets of protein structure data to the International Protein Data Bank.

The goal of interviewing Professor Qin was to gain insights into bacterial detection methods, allowing us to compare our product with traditional methods and identify both its advantages and shortcomings. Additionally, as an expert in food safety, we sought his legal guidance and advice on improving and promoting our product.

Professor Qin provided us with enlightening and unexpected insights. He noted that over 60% of food safety incidents are caused by microorganisms like bacteria. Despite stringent food safety measures, bacteria can still unpredictably enter the food supply chain. To address this, China has enacted regulations, such as the Food Safety Law, which includes microbial control and sets requirements for detection methods, highlighting the government's commitment to food safety.

Professor Qin also discussed other detection methods, such as the cultivation method, which involves creating a suitable environment for a specific bacterium and observing its growth over 1-2 days. He mentioned PCR, an extremely expensive method that takes about half a day. These methods, he pointed out, have their limitations.

He offered valuable suggestions for speeding up our product, such as using chemical catalysts to increase reaction intensity or improving the AuNPs by replacing functional groups or increasing their density. However, he also cautioned that our product's accuracy might be affected by lipids in mixed foods, making it less suitable for testing high-fat and oily foods. To address this, he suggested developing test kits with different functions, such as fruit, meat, and vegetables detection.

Professor Qin also highlighted the importance of market research to understand customer preferences, whether they prefer home testing or sending food to testing institutions. Additionally, he recommended integrating foodborne bacterial infection education to raise public awareness.

We found the interview highly inspiring and are very grateful for Professor Qin's advice. We will continue to develop and enhance our products based on his recommendations in our future business operations.

To continuously improve our products, it is essential to engage in mutual learning with various stakeholders. Their feedback is crucial for understanding how our product impacts the world and how the world influences our product. Therefore, we conducted an interview with Dr. Wang Dongfeng, an experienced doctor specializing in food safety and surgical emergencies at Renmin Hospital of Wuhan University.

We had three main goals during the interview. First, we aimed to compare recent bacteria detection methods. Second, we sought to verify the feasibility and practicality of our product from a clinical perspective. Finally, we hoped to receive suggestions from professionals to upgrade our products, enhance our competitive advantages in the market, meet real-world needs, and contribute positively to society.

Dr. Wang provided us with a wealth of insightful and constructive information and advice. First, he mentioned that, based on his 20 years of experience as a doctor, a significant number of people are infected annually by foodborne bacteria, which aligns with the data we gathered from authoritative sources before the interview. In China, over 80,000 people have been infected by foodborne bacterial diseases, resulting in 1,423 deaths (Li, 2023). Consequently, we must not underestimate the substantial market size of foodborne bacterial infections in China.

However, current bacterial detection methods, such as enzyme-linked immunosorbent assay (ELISA), PCR, and other cultivation approaches, have certain limitations. For instance, bacterial cultivation typically takes 2-3 days, which is very time-consuming. ELISA is also time-consuming and has low sensitivity (Vidal & Catapani, 2005). Dr. Wang emphasized that "producing a reliable and efficient detection method would greatly benefit clinical diagnosis."

These shortcomings of other bacteria detection methods highlight the advantages of our product, which can detect three main bacteria in causing foodborne bacteria diseases, including E. coli, Salmonella, and Staphylococcus aureu. Most importantly, our product could detect the bacteria within 30 minutes and eliminate them within 10 minutes by using infrared ray.

Dr. Wang also advised us to consider other types of bacteria in food, such as Vibrio parahaemolyticus in fish, Bacillus cereus in fruits and vegetables, Clostridium botulinum in grains, and Pseudomonas cocovenenans in mushrooms. He stated, “If the credibility of the results is over 80%-90%, the clinical significance is substantial. Combined with the patient's condition and physical examination, targeted treatment is possible at the early stage of onset.”

Additionally, Dr. Wang suggested that for our product to be used in daily life, it must be easy to operate and accessible. Factors like convenience, portability, environmental friendliness, and global sustainability should be considered. The results should be easy to understand for people with different education levels. He recommended displaying the results with four levels: “completely safe,” “likely harmful,” “probably harmful,” and “completely harmful.” Furthermore, he advised expanding our experiment to include two more targeted bacteria, Clostridium botulinum and Pseudomonas covenants, due to their high toxicity and resistance to high temperatures, which can cause death from respiratory failure.

In summary, following our discussion with Dr. Wang, we relayed his feedback to our laboratory team, who have since refined and adjusted our product by incorporating a broader range of bacterial types. This conversation also encouraged us to consider the diverse needs of stakeholders and the general public, leading us to categorize our test results into four levels to facilitate easier understanding for a wider audience.

China Weipu Company, established in 2008 and headquartered in Shanghai, is a large-scale research and testing institution dedicated to leveraging technology services to impact global change. Weipu operates across five major fields: advanced manufacturing, biomedicine, beauty and health, ecological environment protection, and food and agricultural products. With extensive industry expertise and six core service capabilities—analysis and testing, evaluation, R&D services, intellectual property, metrology calibration, and certification audits—Weipu offers personalized and comprehensive technology services. The company boasts a national presence with branches in 30 cities and more than 50 specialized laboratories staffed by over 3,000 professionals. Weipu holds various accreditations, including CNAS, CMA, NMPA cosmetics registration and filing, customs import and export commodity inspection and appraisal, and agricultural product CATL qualification. Annually, Weipu issues over 270,000 technical reports, serving a client base exceeding 140,000, including numerous Fortune 500 companies. Upholding the philosophy of "Service, More than Testing!", Weipu is dedicated to advancing technology, enhancing product quality, and fostering a safer, healthier, and greener human life.

The primary objective of this visit is to conduct field research aimed at understanding current market demand for bacterial detection, including specific requirements for detection speed, accuracy, and cost-effectiveness. Additionally, the visit seeks to gain insights into the practical application of detection equipment across various stages of food production, processing, storage, and transportation. By engaging in technical exchanges with food testing companies in Shanghai, our team aims to learn from advanced experiences in bacterial detection technology, equipment manufacturing, and data analysis, thereby enhancing our technical capabilities. Furthermore, consultations with company leaders will focus on addressing pertinent issues to further refine our product offerings, stimulate team innovation, and drive technological advancement.

During the factory visit and discussions with the manager, it became evident that our product lacks the necessary reliability to reassure consumers. To address this issue, an experiment comparing our product's results with conventional methods has been planned. The conventional method involves sampling from the food source and diluting its concentration. Once the bacteria are cultured, the count is determined by CFU and concentration multiplication, ensuring high accuracy and reliability. Our detection results will be compared against this method, documenting any errors or misjudgments. Through these trials, the false negative and false positive rates will be calculated and presented to consumers to enhance product trust and transparency.

According to the manager, our combination of three materials for testing three bacteria species is an innovative advancement in rapid testing. Unlike most standard tests that detect one bacteria type, our design focuses on more common solid food bacteria. However, our reagents cannot detect aquatic bacteria like Norovirus, limiting their utility. To overcome this, he suggested leveraging our project's flexibility by combining gold nanoparticles with various PBPs to broaden the range of detectable bacteria species. This enhancement will enhance our product's competitiveness and market advantages. Additionally, the manager emphasized the need to specify whether our product is suitable for testing solid materials, liquids, or both, which will significantly impact our future testing and choice of bacteria species.

During the visit to the company's laboratory and discussions with the manager, we learned about the differences between legal and rapid inspections for food safety. Legal inspections, mandated by law, ensure accurate and legally valid results but take several days. In contrast, rapid testing delivers results in about thirty minutes, making it faster and more efficient for urgent situations. It became apparent that our product's testing speed does not significantly exceed that of rapid inspections, making it difficult to persuade customers to switch from their current products. Therefore, improving our detection speed is crucial to enhancing attractiveness and cost-effectiveness, thus boosting product sales.

Through detailed introductions by the manager and inspection experts at Weipu Company, I gained insights into food safety inspections categorized as legal and rapid. Legal inspections are legally required and provide thorough and accurate results, albeit over a longer period. Rapid inspections, on the other hand, deliver quicker results, which are advantageous in time-sensitive scenarios. Our product aligns with rapid inspections, and with professional guidance, we are better positioned to effectively market our products.

Therefore, based on discussions with professionals, our target consumers could include Market Regulatory Departments, Food Manufacturers, and Individual Food Businesses. These discussions have highlighted the following market demands:

Food Safety: Government agencies, food manufacturers, and restaurant operators must ensure the safety of products for public consumption.

Rapid Detection:Utilizing gold nanoparticles for bacteria detection accelerates and improves the effectiveness of the process compared to traditional methods.

Limited Competition: Few companies currently use nanoparticle technology for food safety evaluation, making our product novel and appealing to consumers and the market.

1) Huang，W.(2015). Prevention and Control of Foodborne Diseases. Interview Review-Shenzhen Municipal Health Commission Website. https://wjw.sz.gov.cn/gzcy/zxft/fthg/content/post_3139645.html
2) 2、Li, N. (2023, November 24). Transcript of the press conference of the National Health Commission on November 24, 2023. Chinese Government Net. http://www.nhc.gov.cn/xcs/s3574/202311/4b4569ebb26f4d2583763780c85c7ba4.shtml
3) Vidal, A. M., & Catapani, W. R. (2005). Enzyme-linked immunosorbent assay (ELISA) immunoassaying versus microscopy: Advantages and drawbacks for diagnosing giardiasis. Sao Paulo Medical Journal, 123(6), 282–285. https://doi.org/10.1590/s1516-31802005000600006
4) World Health Organization. (2018). Salmonella (non-typhoidal). https://www.who.int/news-room/fact-sheets/detail/salmonella-(non-typhoidal)
5) Xu,Q. (2021). Aspergillus infections. Aspergillus Infection Symptoms_Causes_Treatment_Identification_Expert Consultation|Dr. Clove. https://dxy.com/disease/25892/detail