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Updated: Jul 10, 2026
Multiplex Detection of Bacteria in Complex Clinical and Environmental Samples using Oligonucleotide-coupled Fluorescent Microspheres
Published on: October 23, 2011
Ultra-sensitive fluorescent biosensor for multiple bacteria detection based on CDs/QDs@ZIF-8 and microfluidic
Fengchun Huang1,2,3, Chongsi Sun1,2, Jinying Dong1,4
1National Key Laboratory of Biochemical Engineering, PLA Key Laboratory of Biopharmaceutical Production & Formulation Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
A novel fluorescent biosensor detects multiple pathogenic bacteria with high sensitivity. This system utilizes zeolitic imidazolate frameworks (ZIF-8) and microfluidics for rapid, automated bacterial identification in samples.
Area of Science:
- Analytical Chemistry
- Biotechnology
- Materials Science
Background:
- Accurate and rapid detection of multiple pathogenic bacteria is crucial for public health and food safety.
- Existing methods often lack sensitivity, speed, or the ability to simultaneously detect various bacterial species.
- Development of advanced biosensing platforms is needed for improved bacterial surveillance.
Purpose of the Study:
- To develop an ultra-sensitive fluorescent biosensor for simultaneous detection of multiple target pathogenic bacteria.
- To integrate zeolitic imidazolate frameworks (ZIF-8) with quantum dots (QDs) and carbon dots (CDs) for signal amplification.
- To employ a microfluidic fluidized bed for automated sample pretreatment and bacterial capture.
Main Methods:
- Fabrication of CDs/QDs@ZIF-8 nanocomposites for fluorescence signal amplification.
- Utilizing magnetic nanoparticles (MNPs) within a microfluidic fluidized bed for automated capture of target bacteria (E. coli O157:H7, S. paratyphi A, S. paratyphi B).
- Employing a neutral Na2EDTA solution for efficient dissolution of ZIF-8 and release of fluorescent probes without signal loss.
Main Results:
- The developed biosensor achieved simultaneous detection of three pathogenic bacteria with a limit of detection as low as 10^1 CFU/mL.
- Detection was completed within 1.5 hours, demonstrating rapid analysis.
- High mean recovery rates (99.18%) in spiked milk samples confirmed the biosensor's practical applicability.
Conclusions:
- The CDs/QDs@ZIF-8 and microfluidic fluidized bed-based fluorescent biosensor offers a rapid, ultra-sensitive, and simultaneous detection method for multiple bacteria.
- The novel use of Na2EDTA for ZIF-8 dissolution and probe release is effective without compromising fluorescence.
- This platform shows significant potential for real-time monitoring of bacterial contamination in food and clinical samples.
