Agar-Integrated Three-Dimensional Microelectrodes for On-Chip Impedimetric Monitoring of Bacterial Viability

Methods Mol Biol. 2022;2393:447-471. doi: 10.1007/978-1-0716-1803-5_23.ABSTRACTMonitoring bacterial viability is critical in food safety, clinical microbiology, therapeutics, and microbial fuel cell applications. Traditional techniques for detecting and counting viable cells are slow, require expensive and bulky analytical tools and labeling agents, or are destructive to cells. Development of low-cost, portable diagnostics to enable label-free detection and in situ probing of bacterial viability can significantly advance the biomedical field (both applied and basic research). We developed a highly sensitive method for the detection of bacterial viability based on their metabolic activity using non-Faradaic impedimetric sensors comprised of three-dimensional (3D) interdigitated microelectrodes (3D-IDME). Specifically, the 3D-IDME is modified with electrolessly deposited gold (Au) nanoparticles which amplify the sensitivity by increasing the sensing area. A nutrient-rich agarose gel as the seeding layer is integrated with the sensor to enable direct culturing of bacteria and probing of their metabolic activity in situ. The proposed platform enables monitoring of bacterial viability, even in lag-phase, as they metabolize and release ionic species into the surrounding environment (nutrient agar layer). The sensor can detect down to 104 CFU/mL (~2.5 CFU/mm2) of Escherichia coli K12 (a model strain) in under 1 h without the need for any labeling. By integrating these sensors with a...
Source: Mol Biol Cell - Category: Molecular Biology Authors: Source Type: research

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Source: Food Microbiology - Category: Food Science Authors: Source Type: research
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Source: Food Microbiology - Category: Food Science Authors: Source Type: research
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Source: Food Microbiology - Category: Food Science Authors: Source Type: research
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Source: Iranian Journal of Parasitology - Category: Parasitology Authors: Source Type: research
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Source: Food Microbiology - Category: Food Science Authors: Source Type: research
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Source: Food Microbiology - Category: Food Science Authors: Source Type: research
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Source: Cell Research - Category: Cytology Authors: Source Type: research
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