Bacteria sensors are critical in reducing food spoilage and minimizing illness and economic losses caused by foodborne diseases. These sensors detect spoilage earlier, negating any potential spread throughout the supply chain, including agriculture, packaging, transport, and retail. Testing for bacteria guarantees safe and fresh products for consumers and greatly improves food safety and quality control.
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Plasma treatment aids in developing bacteria sensors by allowing microfluidic device fabrication and immobilizing biomolecules. Plasma activates material surfaces with reactive functional groups, which is crucial for PDMS bonding. These reactive groups are also useful in immobilizing biomolecules required for biosensor functionality.
Food Packaging Bacteria Sensors
By incorporating bacteria sensors in food packaging, food spoilage can be detected earlier and more efficiently. Chemically inert materials are commonly chosen for packaging to prevent chemical reactions capable of damaging the contents. While this quality benefits food packaging, it provides a challenge for immobilizing biomolecules, which is needed for bacteria detection. To surpass this challenge, plasma treatment can be utilized to impart reactive functional groups to inert material surfaces to bind the biomolecules.
For instance, Chen et al. treated electrospun polymers with plasma to immobilize reporter phages for use as a bacteria sensor. Chen et al. chose poly-3-hydroxybutyrate (PHB) as their packaging material for several preferred qualities, including its chemically inert profile.
PHB, however, cannot bind reporter phages without modifying the surface chemistry. Plasma treatment was incorporated into their process, enabling Chen et al. to bind these reporter phages in high densities and improve the sensitivity and quality of the bacteria sensor.
Microfluidic Bacteria Sensors
Microfluidic devices are cost-effective and portable, enabling food scientists to quickly detect hazardous bacteria like Campylobacter, Salmonella typhimurium, and Escherichia coli. These devices usually use surface-bound antibodies to bind their targeted bacteria before detection.
One example is the Salmonella typhimurium microfluidic biosensor developed by Wang et al. To give fluorescence to the targeted bacteria, two complexes were reacted: magnetic nanoparticles (MNPs) and fluorescent microspheres (FMSs) modified with Salmonella typhimurium monoclonal antibodies (MAbs) and polyclonal antibodies (PAbs), respectively. After separating unreacted complexes, a concentrated solution was added to the microfluidic device, and a fluorescent light source calculated the total bacteria present.
Microfluidic devices are typically used for lab-on-a-chip technologies as the biosensors are portable and allow fast detection. Harrick Plasma Cleaners activate the polydimethylsiloxane (PDMS) surface, creating a strong bond with glass substrates and fabricating microfluidic bacteria sensors.
References
Chen SY, Harrison M, Ng EK, Sauvageau D, Elias AL. “Immobilized Reporter Phage on Electrospun Polymer Fibers for Improved Capture and Detection of Escherichia coli O157:H7”. ACS Food Science & Technology (2021) 1(6):1085-1094 10.1021/acsfoodscitech.1c00101
Cai G, Zheng L, Liao M, Li Y, Wang M, Liu N and Lin J. “A Microfluidic Immunosensor for Visual Detection of Foodborne Bacteria using Immunomagnetic Separation, Enzymatic Catalysis and Distance Indication”. Microchimica Acta (2019) 186(12) 10.1007/s00604-019-3883-x
Hao L, Xue L, Huang F, Cai G, Qi W, Zhang M, Han Q, Wang Z and Lin J. “A Microfluidic Biosensor Based on Magnetic Nanoparticle Separation, Quantum Dots Labeling and MnO2 Nanoflower Amplification for Rapid and Sensitive Detection of Salmonella Typhimurium”. Micromachines (2020) 11(3):281 10.3390/mi11030281
Ma L, Petersen M, Lu X. “Identification and Antimicrobial Susceptibility Testing of Campylobacter Using a Microfluidic Lab-on-a-Chip Device”. Applied and Environmental Microbiology (2020) 86(9):e00096-20 10.1128/AEM.00096-20
Wang S, Zheng L, Cai G, Liu N, Liao M, Li Yanbin, Zhang X and Lin J. “A Microfluidic Biosensor for Online and Sensitive Detection of Salmonella typhimurium using Fluorescence Labeling and Smartphone Video Processing”. Biosensors and Bioelectronics (2019) 140:111333 10.1016/j.bios.2019.111333
Zheng L, Cai G, Qi W, Wang S, Wang M, Lin J. “Optical Biosensor for Rapid Detection of Salmonella typhimurium Based on Porous Gold@Platinum Nanocatalysts and a 3D Fluidic Chip”. ACS Sensors (2019) 5(1):65-72 10.1021/acssensors.9b01472
This information has been sourced, reviewed, and adapted from materials provided by Harrick Plasma.
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