In recent years, public health safety and food quality have escalated as key concerns with the widespread use of antibiotics in agriculture and aquaculture. Among the various antibiotics, kanamycin—a powerful aminoglycoside—has been commonly utilized to treat bacterial infections in animals. However, residues from this antibiotic can linger in food products like fish and milk, leading to potential adverse health effects in humans, such as hearing loss, kidney damage, and allergic reactions. Due to these risks, it becomes imperative to have reliable methods for detecting kanamycin residues in food. In a groundbreaking study published in Analytica Chimica Acta (DOI: 10.1016/j.aca.2023.342141), researchers led by Yao Jun from the College of Food Science and Technology at Sichuan Tourism University have developed a highly sensitive, cost-effective photoelectrochemical (PEC) biosensor that leverages the biotin-avidin system for this very purpose.

The elaborately designed biosensor combines several elements to detect kanamycin efficiently. The novel approach capitalizes on a multiple signal amplification strategy based on carboxylated graphitic carbon nitride (g-C3N4), a two-dimensional material known for its exceptional electronical conductivity and photoreactivity. The sensor employs the high-affinity biotin-avidin interaction, a widely utilized biochemical tool due to its strong binding force, which is crucial in the immobilization of biomolecules on the biosensor’s surface.

The research conducted by Yao Jun presents the first reported instance where g-C3N4 has been integrated with the biotin-avidin system to create a robust biosensor. The coupling strategy ensures a highly dense loading of biotinylated detector molecules, which, when bound to avidin, enhances the sensitivity of kanamycin detection significantly.

The biosensor operates based on a PEC mechanism, where the reaction occurs upon the absorption of light, facilitating electron-hole pair generation, and resulting in a measurable photocurrent. The presence of kanamycin directly influences this photocurrent due to the specific binding between the antibiotic and its corresponding antibodies. This process, termed a “sandwich-type” immunoreaction, leads to a change in the photocurrent, which is proportional to the kanamycin concentration within the sample.

Key Highlights of the Study:

1. The innovative sensor achieves a feat of sensitivity with a lower detection limit unmet by many existing techniques.
2. The use of affordable and easily sourced g-C3N4 makes the sensor economically feasible for wide-scale application.
3. The selectivity and reproducibility of the results highlight the practical utility of the biosensor in various settings, especially in places with limited resources.
4. The system provides a simple yet rapid method of testing, capable of delivering results within a short timeframe without the need for a laboratory setting.
5. Field trials conducted using milk and fish samples affirmed the biosensor’s efficacy in detecting kanamycin, showing potential for real-world applications.

Publications that further support the significance of this study reveal the urgency and need for advancements in biosensing technology for antibiotic residues (Reference 1). Additionally, prior research into the biotin-avidin system elucidates why it’s an ideal candidate for biosensor applications due to its exceptional affinity and specificity (Reference 2). G-C3N4’s properties and applications in various sensing platforms are well documented, affording it as a practical choice for the sensor’s material (Reference 3). Moreover, the dire effects of antibiotic residues in food on human health are extensively studied, stressing the importance of sensitive detection methods (Reference 4). Studies on the mechanisms of photoelectrochemical sensing and its role in modern biosensors provide insights into the underlying scientific principles of the novel kanamycin sensor (Reference 5).


1. Kanamycin detection biosensor
2. Photoelectrochemical biosensing technology
3. Food safety antibiotic residues
4. Biotin-avidin amplification system
5. Graphitic carbon nitride g-C3N4

The study led by Yao Jun lays a significant milestone in food safety and public health surveillance. The proposed biosensor not only addresses the current challenges in antibiotic residue detection but also highlights how innovations in material science and biochemistry can merge to present solutions with profound impacts. This technological leap signals a future where ensuring the absence of harmful antibiotic residues in our food supply chain can be commonplace, reliable, and accessible to all.