title: Using photoluminescent gold nanodots to detect hemoglobin in diluted blood samples.
abstract: In this study we used photoluminescent 11-mercaptoundecanoic acid-bound gold nanodots (11-MUA-Au NDs) to detect hemoglobin through photoluminescence (PL) quenching. The mechanism of quenching, which occurred through redox reactions between the 11-MUA-Au NDs and the Fe(II) atoms of hemin units, was supported by an increase in the signals (G 2.0 and 5.9) of high-spin state Fe(III) ions. The Stern-Volmer quenching constants (Ksv) for hemin, cytochrome c, hemoglobin, and myoglobin were 5.6×10(7), 1.7×10(7), 1.6×10(7), and 6.2×10(6)M(-1), respectively, in good agreement with the order of their reduction potentials. When excited at 375nm, the PL intensity of the 11-MUA-Au NDs at 520nm decreased upon increasing the concentration of hemoglobin from 1.0 to 10nM (R(2)=0.9913). This approach using bovine serum albumin blocked 11-MUA-Au NDs provided a limit of detection for hemoglobin (at a signal-to-noise ratio of 3) of 0.5nM in biological buffer, with great selectivity over other non-heme-containing proteins, including human serum albumin, β-casein, and carbonic anhydrase. We validated the practicality of this approach through the determination of the concentrations (1.85-2.46mM) of hemoglobin in diluted (10(6)-fold) human blood samples based on PL quenching of Au NDs. This simple, sensitive, and selective approach holds great potential for the diagnosis of several diseases, including anemia, erythrocytosis, and thalassemias.
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Li-Yi
authors.initials: LY
authors.lastname: Chen
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Huang
authors.forename: Wei-Yu
authors.initials: WY
authors.lastname: Chen
authors.forename: Han-Jia
authors.initials: HJ
authors.lastname: Lin
authors.forename: Huan-Tsung
authors.initials: HT
authors.lastname: Chang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D008163:Luminescent Measurements / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry*; D045663:Quantum Dots
chemical_list: D006454:Hemoglobins; D006046:Gold