Asymmetric flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry for the quantification of quantum dots bioconjugation efficiency.
Hyphenation of asymmetric flow field-flow fractionation (AF4) to an on-line elemental detection (inductively coupled plasma-mass spectrometry, ICP-MS) is proposed as a powerful diagnostic tool for quantum dots bioconjugation studies. In particular, conjugation effectiveness between a "model" monoclonal IgG antibody (Ab) and CdSe/ZnS core-shell Quantum Dots (QDs), surface-coated with an amphiphilic polymer, has been monitored here by such hybrid AF4-ICP-MS technique. Experimental conditions have been optimized searching for a proper separation between the sought bioconjugates from the eventual free reagents excesses employed during the bioconjugation (QDs and antibodies). Composition and pH of the carrier have been found to be critical parameters to ensure an efficient separation while ensuring high species recovery from the AF4 channel. An ICP-MS equipped with a triple quadropole was selected as elemental detector to enable sensitive and reliable simultaneous quantification of the elemental constituents, including sulfur, of the nanoparticulated species and the antibody. The hyphenated technique used provided nanoparticle size-based separation, elemental detection, and composition analysis capabilities that turned out to be instrumental in order to investigate in depth the Ab-QDs bioconjugation process. Moreover, the analytical strategy here proposed allowed us not only to clearly identify the bioconjugation reaction products but also to quantify nanoparticle:antibodies bioconjugation efficiency. This is a key issue in future development of analytical and bioanalytical photoluminescent QDs applications.
Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julian Claveria 8, E-33006, Oviedo, Spain.
Mario
M
Menéndez-Miranda
Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julian Claveria 8, E-33006, Oviedo, Spain. Electronic address: ruizjorge@uniovi.es.
Jorge Ruiz
JR
Encinar
Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julian Claveria 8, E-33006, Oviedo, Spain. Electronic address: jcostafe@uniovi.es.
José M
JM
Costa-Fernández
Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julian Claveria 8, E-33006, Oviedo, Spain.
Alfredo
A
Sanz-Medel
D019187:Cadmium Compounds / Q000737:chemistry; D031521:Fractionation, Field Flow / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D045663:Quantum Dots / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
D019187:Cadmium Compounds; D007074:Immunoglobulin G; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; C031238:zinc sulfide
Bioconjugation efficiency; Flow field-flow fractionation; Inductively coupled plasma mass spectrometry; Nanoparticle characterization; Quantum Dots