Aptameric photonic structure-based optical biosensor for the detection of microcystin

Area of Science:

• Biomedical Engineering
• Materials Science
• Environmental Science

Background:

• Microcystins (MC) are potent cyanotoxins posing risks to aquatic ecosystems and human health.
• Existing MC detection methods often lack sensitivity, selectivity, or are cost-prohibitive.
• Development of rapid, on-site, and cost-effective biosensors is crucial for public health and environmental monitoring.

Purpose of the Study:

• To develop a novel optical photonic biosensor for sensitive and selective detection of microcystin (MC).
• To utilize an aptamer-immobilized interpenetrating polymeric network (IPN_aptamer) intertwined with solid-state cholesteric liquid crystals (CLC_solids).
• To investigate the colorimetric response of the biosensor to varying MC concentrations.

Main Methods:

• Fabrication of an aptamer-immobilized interpenetrating polymeric network (IPN_aptamer) hydrogel.
• Integration of the IPN_aptamer with solid-state cholesteric liquid crystals (CLC_solids) to form a biosensor chip.
• Monitoring the color shift (wavelength shift) of the biosensor upon exposure to different concentrations of MC.

Main Results:

• The IPN_aptamer-CLC_solid biosensor exhibited a red-shift in color due to increased swelling and helical pitch expansion.
• Upon MC detection, aptamer-mediated engulfment reduced IPN polarity, causing a blue-shift in color.
• A linear relationship was observed between wavelength shift and MC concentration (3.8–150 nM), with a limit of detection of 0.88 nM.

Conclusions:

• The developed optical biosensor provides a simple, low-cost, and sensitive method for MC detection.
• The aptamer-functionalized IPN-CLC system demonstrates high selectivity for MC.
• This platform offers a promising strategy for developing advanced biosensors for various toxins by modifying biological receptors.