Label-Free Liquid Crystal Biosensor Based on Split Aptamers for Detecting Serum Myoglobin

Area of Science:

• Biochemistry
• Biomaterials Science
• Analytical Chemistry

Background:

• Myoglobin (Mb) is a crucial serum biomarker for acute myocardial infarction (MI).
• Accurate and rapid detection of serum Mb is clinically significant for timely diagnosis.
• Existing detection methods may face challenges with sensitivity or complexity.

Purpose of the Study:

• To develop a novel "sandwich" liquid crystal biosensor for label-free myoglobin detection.
• To utilize split aptamers to minimize false-positive signals and enhance specificity.
• To establish a quantitative method for serum Mb detection using optical signal changes.

Main Methods:

• Immobilization of myoglobin aptamer fragments as capture probes on a glass substrate using TEA linkers.
• Specific binding of target myoglobin to capture probes, followed by reassociation with signal aptamer probes.
• Induction of changes in 5CB liquid crystal molecule alignment detected via polarizing microscopy.
• Label-free quantitative detection based on optical signal variations (brightness and color).

Main Results:

• The biosensor successfully detected myoglobin in a concentration range of 0.05 to 130 ng/mL.
• A low limit of detection (LOD) of 0.045 ng/mL was achieved.
• The "Apt-target molecule-Apt" configuration demonstrated high specificity and sensitivity.

Conclusions:

• The developed liquid crystal biosensor provides a simple, label-free, and highly specific method for serum myoglobin detection.
• This biosensing approach shows significant potential for the rapid and accurate quantification of cardiac biomarkers.
• The use of split aptamers effectively enhances the reliability of the biosensor.