Photonic Aptasensor Based on the Smart Cholesteric Liquid Crystal Network Structure for Cylindrospermopsin Detection

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Solid-state cholesteric liquid crystals (CLC_solid) offer a tunable photonic structure for optical sensing applications.
• Developing selective and sensitive biosensors for waterborne toxins is crucial for public health.

Purpose of the Study:

• To design and fabricate a CLC_solid-based optical biosensor for the selective detection of cylindrospermopsin toxin (CYT).
• To evaluate the performance of the developed biosensor in terms of sensitivity, selectivity, and detection range.

Main Methods:

• Fabrication of a CLC_solid photonic structure integrated with an interpenetrating polymeric network (IPN).
• Immobilization of a cylindrospermopsin aptamer (CY9) onto the IPN for specific CYT recognition.
• Monitoring color shifts in the photonic structure upon CYT binding to quantify the toxin concentration.

Main Results:

• The developed IPN_CY9 biosensor chip exhibited a blue shift in color upon exposure to CYT.
• The biosensor demonstrated selective detection of CYT within a linear range of 4.2–120 nM.
• A low limit of detection (LOD) of 2.55 nM was achieved for CYT detection.

Conclusions:

• The CLC_solid-IPN_CY9 biosensor provides a sensitive and selective method for detecting CYT in water.
• The sensor's mechanism relies on aptamer-toxin binding-induced hydrogel shrinkage and photonic structure alteration.
• This approach offers a promising strategy for developing portable toxin detection kits for remote monitoring.