Rapid and sensitive detection of hemoglobin with gold nanoparticles based fluorescence sensor in aqueous solution

Abstract A novel gold nanoparticles (AuNPs)-based fluorescence assay had been developed for the detection of hemoglobin (Hb). The method relied on the high selectivity of surface imprinting technique and the strong fluorescence property of AuNPs. Herein, firstly, the carboxyl modified AuNPs were initially anchored on the amino-functionalized silica nanoparticles under the assistance of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 1-hydroxy-5-pyrrolidinedione (NHS). Then, the Hb-imprinted polymer layer was wrapped on the surface of SiO2/AuNPs via a sol–gel surface imprinting technique. The generated SiO2/Au/MIPs as fluorescence sensor owned both sensitive detection of AuNPs and specific selectivity of molecularly imprinted polymer. The conditions such as pH, stability and effect of the fluorescence sensor concentration were investigated to search the optimized detection conditions. For the optimized conditions, the fluorescence-quenching detection presented a satisfactory linearity with Hb concentrations in the range of 0.1–20 μmol L−1 and the detection limit was 0.03 μmol L−1. Moreover, through the investigation of selective and competitive quenching, the fluorescence sensor exhibited satisfying selectivity and high binding affinity to Hb under the existence of its possibly competing molecules, such as bovine serum albumin (BSA), bovine hemoglobin (BHb), albumin, chicken egg (ACE). The results proved that the fluorescence sensor was succeeded to be used in the field of rapid recognition and determination of Hb even though existing of other complex proteins.