Classification of analytics, sensorics, and bioanalytics with polyelectrolyte multilayer capsules.

Area of Science:

• Materials Science and Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Polyelectrolyte multilayer (PEM) capsules, fabricated via layer-by-layer (LbL) adsorption on sacrificial templates, are versatile carriers and analytical tools.
• Existing literature lacks a comprehensive classification of the diverse analytical and sensoric functionalities of PEM capsules.
• Traditional chemical analytics is only one facet of the broader analytical landscape.

Purpose of the Study:

• To classify the analytics, sensorics, and biosensorics functionalities of PEM capsules and coated particles.
• To organize these functionalities based on the stimuli they respond to and their application areas.
• To provide a foundational understanding of the existing capabilities and guide future research directions.

Main Methods:

• Systematic classification of PEM capsule applications based on stimuli and application domains.
• Identification of three primary categories: chemical analytics, physical sensorics, and biosensorics/bioanalytics.
• Review and discussion of detection principles for various stimuli including chemical, physical, and biological inputs.

Main Results:

• Categorization into: (I) Chemical analytics (pH, ion, O2, H2O2 sensing, SERS), (II) Physical sensorics (temperature, mechanical, osmotic pressure), and (III) Biosensorics/Bioanalytics (fluorescence, glucose, urea, protease sensing, theranostics).
• Demonstration of the broad range of analytical and bioanalytical tools developed using PEM capsules.
• Establishment of a framework for understanding the stimuli-response relationships in capsule-based sensing.

Conclusions:

• The classification highlights the extensive analytical and bioanalytical potential of PEM capsules across various stimuli.
• This framework aids in recognizing the breadth of current applications and strategically positioning future developments.
• PEM capsules are powerful platforms for creating advanced chemical, physical, and biological sensors and theranostics.