Corchorus olitorius-derived green carbon dots: A single nanomaterial for multiplexed applications in sensing, catalysis, and critical micelle concentration analysis.

The creative generation of multifunctional carbon dots (CDs) to concurrently accomplish miscellaneous targets is highly pertinent in real-world applications. Therefore, designing CDs that exhibit superlative execution in drug and temperature sensing, catalysis, and critical micelle concentration (CMC) determination is brilliant. This study presents the synthesis of unique blue-emissive nitrogen-doped carbon dots (N-CDs) from Corchorus olitorius (molokhia) using a clean, rapid microwave method. We demonstrate that these N-CDs serve as a versatile nanoplatform through a "four birds, one stone" strategy, excelling in four distinct applications: (1) sensitive drug sensing, (2) temperature sensing, (3) critical micelle concentration (CMC) determination, and (4) photocatalytic dye degradation. As a nanosensor, the N-CDs enable the highly sensitive detection of the antiglaucoma drug timolol maleate (TIM) via a fluorescence quenching mechanism, achieving a remarkable limit of detection (LOD) as low as 0.49 μM. This ability was effectively applied to quantify TIM in eye drops, artificial aqueous humor, and environmental water samples. Furthermore, the N-CDs function as an efficient fluorescent thermosensor across a physiologically relevant range (30-70 °C), a facile probe for determining the CMC of surfactants, and a potent visible-light-driven photocatalyst for methylene blue degradation. This work pioneers a sustainable path for converting biomass into high-value-added N-CDs, providing a cost-effective and environmentally friendly multifunctional nanoprobe aligned with sustainable development goals.