TEMED enhanced photoluminescent imaging detection of proteins in human serum using quantum dots after PAGE

In this paper, the development of a novel enhanced photoluminescent (PL) imaging method for human serum proteins detection after polyacrylamide gel electrophoresis (PAGE) is described. Thioglycolic acid (TGA)-capped CdTe QDs and enhanced reagent tetramethylethylenediamine (TEMED) have been introduced, resulting in direct detection of various proteins in native polyacrylamide gels and expanded application scope to SDS gels. Some relatively low-abundance proteins such as Zinc-α(2)-glycoprotein (ZAG) and α(2)-HS-glycoprotein (α(2)-HSG) are easily detected by TEMED enhanced PL imaging and identified by MS and MS/MS techniques. In the present study, the PL imaging conditions such as QDs concentration, alkali concentration, and enhanced reagents are optimized and the possible mechanisms are analyzed. The sensitivity of TEMED enhanced PL imaging is satisfying, with a linear range of 11.7-375 ng for ferritin, comparing with 46.9-375 ng in CBB-R250 staining and 23.4-375 ng in direct PL imaging. As a novel PL imaging detection method that is simple, fast, and sensitive, it shows great analytical potential in proteome research and in biochemistry.