Enhancement of Growth and Lipid Production in Microalgae Using Aggregation-Induced Emission Based Luminescent Material for Sustainable Food and Fuel

Aggregation-Induced Emission (AIE) based nanomaterials are progressively gaining momentum owing to their evolvement into an interdisciplinary field ranging from biomass and biomolecule yield to image-guided photodynamic therapy. This study focuses on a novel strategy to enhance growth, lipid accumulation, and in vivo fluorescence visualisation in green microalgae Chlamydomonas reinhardtii using AIE nanoparticles to quantify radical changes. The absorption of AIE photosensitiser (PS), TTMN (C₂₆H₁₇N₃S[M]⁺) was recorded from 420 to 570 nm with a peak at 500 nm, and the emission ranged from 550 to 800 nm with a peak at 650 nm. As a reactive oxygen species (ROS) molecule, H₂O₂ generation of TTMN in C. reinhardtii cells was detected with AIE nanoprobes TPE-BO (C₃₈H₄₂B₂O₄). H₂O₂ accumulation increased with the increase of TTMN concentrations. The maximum growth (2.1×10⁷ cell/mL) was observed at 10 μM TTMN-exposed C. reinhardtii cells. Significant lipid accumulation was found in both 10 and 15 μM TTMN-treated cells. For lipid visualisation, an AIE nanoprobe, 2-DPAN (C₂₄H₁₈N₂O) was used, and superior fluorescence was determined and compared with the traditional BODIPY dye. Cytotoxicity analysis of 10 μM TTMN on the HaCat cell line with 86.2 % cell viability revealed its high biocompatibility on living cells. This AIE-based nanotechnology provides a novel approach for microalgae-derived sustainable biomass and eco-friendly biofuel production.