Designed synthesis of dual emitting silicon quantum dot for cell imaging: Direct labeling of Alpha 2-HS-Glycoprotein.

The innocent silicon quantum dots (SQDs) having dual emissive property (blue in VIS and red in NIR), high photo stability and free from auto fluorescence are designed and synthesized for the first time using ethylene glycol. A new attempt has been made for direct labeling of Alpha 2-HS-Glycoprotein (Fetuin A) through functionalizing of the synthesized dots by EDC coupling. The SQDs were characterized by FTIR, TEM, AFM, XRD, EDX, DLS and TGA. The chemistry involves in the synthesis and functionalization of dots is elucidated in details. The synthesized SQDs are suitable for live cell imaging as well as direct labeling of the Fetuin A in the NIR region. The developed direct labeling technique of Fetuin A imaging is robust, more specific and simple, which reduces the number of incubation, washing steps and produce better quality data compared to the conventional method using Rhodamine B.