Composite diatom fluorescent sensor substrate enriched with CdSe/ZnS quantum dots on the surface by biofabrication

Area of Science:

• Biomaterials Science
• Nanotechnology
• Biophotonics

Background:

• Diatoms possess intricate micro- and nanostructures with unique photonic properties.
• Quantum dots (QDs) offer tunable fluorescence but can suffer from instability.

Purpose of the Study:

• To develop a stable and sensitive fluorescent biosensor using biofabricated QD-Diatom substrates.
• To investigate the immobilization of Cadmium Selenide/Zinc Sulfide (CdSe/ZnS) QDs onto diatom biosilica.

Main Methods:

• Biofabrication of QD-Diatom substrate by immobilizing CdSe/ZnS QDs onto diatom biosilica.
• Toxicity assessment of QDs at a concentration of 7.5×10^-3 nmol/mL on diatom growth.
• Investigating purification methods using Sodium Dodecyl Sulfate (SDS), NaOH, and calcination at 180 °C.

Main Results:

• QD-Diatom preserves diatom porosity and enhances QD fluorescence stability.
• QD-Diatom exhibits enhanced fluorescence intensity and red-shifted emission upon binding to target molecules (DBs).
• Purification methods (2% SDS, NaOH, or calcination) effectively removed organic pigments while maintaining QD fluorescence activity.

Conclusions:

• QD-Diatom is a promising new fluorescent biosensor substrate fabricated through a simple biofabrication process.
• The QD-Diatom platform demonstrates potential for sensitive molecular detection with improved fluorescence characteristics.
• Biofabrication offers a viable method for creating advanced biosensing materials by combining biological structures with nanomaterials.