This patent presents an ultrasensitive U-bend fiber optic sensor for rapid quantitative detection of beta-lactam antibiotics (ampicillin, amoxicillin, ceftazidime, cefotaxime) in milk, chicken meat, water, and wastewater. Using TEM beta-lactamase immobilized on polyaniline, the sensor measures localized pH changes from enzymatic hydrolysis, correlating to antibiotic concentration. Validated for various samples, it offers a quick, accurate solution for monitoring antibiotic residues, crucial for addressing antimicrobial resistance.
Figure (1) Schematic representation of the mechanism of sensing of beta lactam antibiotics (example shown with ceftazidime); (2)(a) FEG-TEM analysis of polyaniline nanofibers (b) FEG-SEM analysis of polyaniline nanofiber coated optical fiber.
Excessive antibiotic use in livestock has led to a rise in antimicrobial resistance (AMR), posing a significant threat to human health. Current detection methods for antibiotic residues in food, water, and wastewater are complex and costly, making them inaccessible to small and medium-scale farms. There is an urgent need for simple, costeffective, and scalable technologies to detect and quantify beta-lactam antibiotics to ensure food safety and combat AMR.
- Rapid Detection: The U-bend fiber optic sensor design enables quick identification of beta-lactam antibiotics, significantly reducing the analysis time required for testing samples.
- High Sensitivity: The sensor demonstrates an impressive detection capability, with sensitivity as low as 0.1 μg/L, allowing for ultrasensitive monitoring of antibiotic residues across a broad concentration range (0.18 nM to 1800 nM).
- Versatility: The sensor has been validated for use with a variety of sample types, including cow milk, buffalo milk, packaged milk, chicken meat, and tap water, making it highly adaptable for different monitoring scenarios.
- Broad Antibiotic Detection: It is capable of detecting a wide spectrum of beta-lactam antibiotics, including Penicillins, Cephalosporins, Carbapenems, and Monobactams, enhancing its utility in both food safety and environmental surveillance.
The prototype of the developed optical sensor for beta-lactam antibiotics involves High-OH, silica core, multimode optical fibers with a core diameter of 200 μm were procured from Thorlabs®, cut into 40 cm strips, and polished at the ends. A 2 cm portion of the fiber was dejacketed, decladded, and bent into a 'U' shape with a 1.5 mm bend diameter using a butane flame for optimal sensitivity. The fibers were cleaned using a sequence of 1M sodium hydroxide, a 1:1 methanol and hydrochloric acid mixture, and sulphochromic acid. The cleaned U-bend region was modified with polyaniline nanofibers through oxidative polymerization of aniline in the presence of ammonium persulfate as an initiator, confirmed by peak absorbance at 650 nm. The polyaniline-coated fibers were further functionalized by incubating them in glutaraldehyde and immobilizing recombinant E. coli Beta lactamase TEM precursor protein, followed by blocking remaining amine sites with bovine serum albumin. The sensor's response to beta-lactam antibiotics was monitored as a change in absorbance at 440 nm, with calibration curves developed for ceftazidime in water, milk, meat, and wastewater matrices. The sensor demonstrated high sensitivity with detection limits of 0.1 μg/L in milk and water, and 5 μg/kg in chicken meat. Reusability was confirmed up to three uses with minimal error. The sensor's universal applicability across various matrices was achieved by adjusting pH and minimal sample preparation, primarily fat removal from milk. The technology utilizes enzymatic hydrolysis of beta-lactams by beta-lactamase, causing a localized pH change detected optically by the polyaniline-modified fibers.
A functional optical fiber-based sensor has been developed and successfully validated in laboratory conditions using real-world sample matrices such as milk, chicken meat, and tap water. The sensor demonstrates excellent sensitivity (down to 0.18 nM), selectivity toward βlactam antibiotics, and reusability. Calibration curves and performance metrics have been established; however, GLP-compliant animal studies, regulatory submissions, and clinical evaluations are yet to be initiated.
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Improving public health, this approach reduces human exposure to antibiotic residues, thereby lowering the risk of developing antibiotic resistance. It also enhances food safety by ensuring that dairy and meat products are free from harmful antibiotic contaminants, protecting consumers from potential health hazards. In addition, environmental protection is supported through the monitoring of wastewater for antibiotic contamination, contributing to cleaner and more sustainable ecosystems. The system aids regulatory compliance by helping food producers and water treatment facilities meet stringent standards, thus avoiding penalties and ensuring public trust. Moreover, it benefits agriculture by assisting farmers in maintaining high product quality, ultimately increasing market acceptance and consumer confidence.
- Dairy Industry: Rapid detection of antibiotic residues in milk.
- Poultry Sector: Screening of meat for antibiotic contamination.
- Environmental Monitoring: Trace antibiotic detection in water bodies and effluents.
- Agriculture: Residue monitoring in livestock and farming practices.
- Food Processing: Quality control in processed food products.
- Regulatory Authorities: Ensuring compliance with residue limits.
- Testing Laboratories: Routine analysis and safety validation.
- Public Health Agencies: Surveillance of antibiotic contamination risks.
Geography of IP
Type of IP
202021004428
474621