Cartoon Scientist Cartoon Scientist with Microscope Friendly Bacteria DNA Helix

Inspiration

Pharmaceutical residues are increasingly recognized as silent pollutants with serious consequences for human health and the environment. Unlike many contaminants, these compounds are biologically active at low levels of concentration, meaning even trace concentrations can disrupt ecosystems and drive antimicrobial resistance, one of the most urgent global health threats. Wastewater treatment plants are not designed to completely remove pharmaceutical substances, allowing residues of antibiotics, pain relievers, and other drugs to accumulate in rivers, soils, and even the food chain (McGill University, 2025; WHO, 2024). This persistence compels urgent attention to identify and tackle the most significant pharmaceutical pollutants.

Pharmaceutical pollution impact

A Local Problem

Hong Kong river contamination

In Hong Kong, environmental monitoring and medical usage surveys highlight that tetracyclines and salicylates are particularly relevant. Tetracyclines are widely prescribed for common infections such as pneumonia, bronchitis and skin conditions, while salicylates (notably aspirin) are commonly used for cardiovascular diseases and pain relief. Their intensive use means that these drugs are routinely excreted into local sewage systems, where inadequate removal raises contamination risks. Studies in Hong Kong rivers, including the Kai Tak and Kam Tin systems, have already revealed antibiotic residues exceeding international safety thresholds, with evidence pointing to links between pharmaceutical pollution and antimicrobial resistance in aquatic bacteria (HK Environmental Monitoring Data, 2025). For a dense urban city reliant on vulnerable marine ecosystems for food supply, this contamination not only threatens public health—via resistant infections and chronic exposure—but also endangers food security, as residues accumulate in fish and seafood sourced from local waters.

A Global Issue

The concerns surrounding tetracyclines and salicylates are not unique to Hong Kong. Globally, studies have raised alarm about these compounds. A McGill University-led assessment estimated 8,500 tonnes of antibiotics enter rivers every year, with tetracyclines ranking among the most frequently detected classes (McGill University, 2025). In Latin America, a Scientific Reports study showed that children’s urine contained multiple antibiotics, including doxycycline, even without recent medical treatment, demonstrating environmental exposure as a major pathway (Zirena Vilca et al., 2025). Similarly, salicylates have been detected in waterways in Europe and Asia, where they contribute to aquatic toxicity and bioaccumulation risks (WHO, 2024; Fortune Journals, 2019). Together, the evidence underscores that tetracyclines and salicylates are not isolated pollutants but part of a global pattern of pharmaceutical contamination, making them priority targets for monitoring and remediation.

Global antibiotic pollution
Salicylate contamination in waterways

Our Goals

    • Apply synthetic biology to detect pharmaceutical residues, focusing on tetracycline and salicylate.
    • Develop biodegradation modules to break down detected pollutants.
    • Create a portable, automated biosensing platform that detects and analyzes pollutants in water in real time.

Tackle the Problem with Synthetic Biology

Our project applies synthetic biology to design a system that can both detect and degrade pharmaceutical waste—specifically tetracycline and salicylate—in contaminated water sources. By combining biosensing and bioremediation, we aim to create a complete and eco-friendly solution for pollution monitoring and treatment.

Key Design Features:

Detection:

  • Tetracycline biosensor utilizes the TetR/pTet regulatory system.
  • Salicylate biosensor employs the NahR/pSal regulatory system.
  • Both use chromoproteins (amilCP, mRFP1e) as visible reporters for easy detection without specialized equipment.

Degradation:

  • TetX enzyme breaks down tetracycline into non-toxic products.
  • NahG and XylE enzymes convert salicylate into harmless metabolites.

These modules together provide a synergistic biological approach to identify and remove pharmaceuticals from water environments.

Build An Integrated AI-Powered Biosensing Platform

We built Remedix to address the growing challenge of pharmaceutical and antibiotic pollution in water, particularly in areas where conventional testing is expensive, complex, and limited to specialized laboratories. Existing methods like ICP-MS are highly accurate but cost-prohibitive and inaccessible for regular monitoring by farmers, technicians, or local communities.

Our goals in creating Remedix:

  • Make biosensing accessible through a low-cost, portable, and automated system.
  • Translate synthetic biology into real-world solutions for environmental monitoring.
  • Ensure safety and usability using alginate-encapsulated bacterial biosensors.
  • Enable real-time detection and response with AI-driven analysis and IoT connectivity.
  • Bridge the gap between lab research and field application to support large-scale water quality management.

References

  • McGill University. (2025). Study finds antibiotics from human use are contaminating rivers worldwide. Smart Water Magazine.
  • WHO. (2024). Health-care waste. WHO Fact Sheets. https://www.who.int/news-room/fact-sheets/detail/health-care-waste
  • Local Hong Kong Environmental Monitoring Data. (2025).
  • Zirena Vilca, F., et al. (2025). Presence of antibiotics in children's urine: a silent risk beyond drinking water. Scientific Reports, 15, 12078.
  • Fortune Journals. (2019). Health care waste: Avoiding hazards to living and non-living environment by efficient management.