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Ultrasensitive Detection of Biomarkers by Using a Molecular Imprinting Based Capacitive Biosensor
Published on: February 16, 2018
Thermal Pyocyanin Sensor Based on Molecularly Imprinted Polymers for the Indirect Detection of Pseudomonas aeruginosa
Margaux Frigoli1, Joseph W Lowdon1, Manlio Caldara1
1Sensor Engineering Department, Faculty of Science and Engineering, Maastricht University, P.O. Box 616, 6200 MDMaastricht, The Netherlands.
Abstract:
Pseudomonas aeruginosa is a ubiquitous multi-drug-resistant bacterium, capable of causing serious illnesses and infections. This research focuses on the development of a thermal sensor for the indirect detection of P. aeruginosa infection using molecularly imprinted polymers (MIPs). This was achieved by developing MIPs for the detection of pyocyanin, the main toxin secreted by P. aeruginosa. To this end, phenazine was used as a dummy template, evaluating several polymeric compositions to achieve a selective MIP for pyocyanin recognition. The sensitivity of the synthesized MIPs was investigated by UV-vis analysis, with the best composition having a maximum rebinding capacity of 30 μmol g-1 and an imprinting factor (IF) of 1.59. Subsequently, the MIP particles were immobilized onto planar aluminum chips using an adhesive layer, to perform thermal resistance measurements at clinically relevant concentrations of pyocyanin (1.4-9.8 μM), achieving a limit of detection (LoD) of 0.347 ± 0.027 μM. The selectivity of the sensor was also scrutinized by subjecting the receptor to potential interferents. Furthermore, the rebinding was demonstrated in King's A medium, highlighting the potential of the sensor for the indirect detection of P. aeruginosa in complex fluids. The research culminates in the demonstration of the MIP-based sensor's applicability for clinical diagnosis. To achieve this goal, an experiment was performed in which the sensor was exposed to pyocyanin-spiked saliva samples, achieving a limit of detection of 0.569 ± 0.063 μM and demonstrating that this technology is suitable to detect the presence of the toxin even at the very first stage of its production.
Insights
This study developed a novel thermal sensor using molecularly imprinted polymers (MIPs) to detect pyocyanin, a toxin from Pseudomonas aeruginosa. The sensor shows promise for early clinical diagnosis of infections.
Area of Science:
- Biomaterials Science
- Chemical Sensors
- Microbiology
Background:
- Pseudomonas aeruginosa is a multi-drug-resistant bacterium causing severe infections.
- Pyocyanin is a key toxin produced by P. aeruginosa, indicating infection.
- Accurate and early detection methods are crucial for effective treatment.
Purpose of the Study:
- To develop a thermal sensor for indirect detection of P. aeruginosa infection.
- To create selective molecularly imprinted polymers (MIPs) for pyocyanin recognition.
- To validate the sensor's performance in complex biological samples.
Main Methods:
- Synthesized MIPs using phenazine as a dummy template for pyocyanin.
- Evaluated MIP selectivity and sensitivity using UV-vis spectroscopy.
- Immobilized MIPs on aluminum chips for thermal resistance measurements.
- Tested sensor performance with pyocyanin in King's A medium and spiked saliva samples.
Main Results:
- Achieved a maximum rebinding capacity of 30 μmol g-1 and an imprinting factor of 1.59 for MIPs.
- Established a limit of detection (LoD) of 0.347 ± 0.027 μM for pyocyanin on the sensor.
- Demonstrated sensor functionality in complex media and saliva samples.
- Achieved an LoD of 0.569 ± 0.063 μM in spiked saliva, indicating early-stage detection capability.
Conclusions:
- Developed a selective and sensitive MIP-based thermal sensor for pyocyanin detection.
- The sensor demonstrates potential for indirect diagnosis of P. aeruginosa infections.
- The technology is suitable for detecting early-stage toxin production in clinical samples like saliva.
