Multimodal cleavable reporters vs conventional labels for optical quantification of amino and carboxy groups on nanomaterials and microparticles
- Carboxy, amino, and thiol groups play a critical role in a variety of physiological and biological processes and are frequently used for bioconjugation reactions. Moreover, they enable size control and tuning of the surface during the synthesis of particle systems. Especially, thiols have a high binding affinity to noble metals and semiconductors (SC). Thus, simple, inexpensive, robust, and fast methods for the quantification of surface groups and the monitoring of reactions involving ligands are of considerable importance for the characterization of modified or stabilized nanomaterials including polymers. We studied the potential of the Ellman’s assay, recently used for the quantification of thiol ligands on SC nanocrystals by us1 and the 4-aldrithiol assay for the determination of thiol groups in molecular systems and on polymeric, noble and SC nanomaterials. The results were validated with ICP-OES and reaction mechanisms of both methods were studied photometrically and withCarboxy, amino, and thiol groups play a critical role in a variety of physiological and biological processes and are frequently used for bioconjugation reactions. Moreover, they enable size control and tuning of the surface during the synthesis of particle systems. Especially, thiols have a high binding affinity to noble metals and semiconductors (SC). Thus, simple, inexpensive, robust, and fast methods for the quantification of surface groups and the monitoring of reactions involving ligands are of considerable importance for the characterization of modified or stabilized nanomaterials including polymers. We studied the potential of the Ellman’s assay, recently used for the quantification of thiol ligands on SC nanocrystals by us1 and the 4-aldrithiol assay for the determination of thiol groups in molecular systems and on polymeric, noble and SC nanomaterials. The results were validated with ICP-OES and reaction mechanisms of both methods were studied photometrically and with ESI-TOF-MS. The investigation of the reaction mechanisms of both methods revealed the influence of different thiols on the stoichiometry of the reactions2, yielding different mixed disulfides and the thiol-specific products spectroscopically detected. The used methods can quantify freely accessible surface groups on nanoparticles, e.g., modified polystyrene nanoparticles. For thiol ligands coordinatively bound to surface atoms of, e.g., noble or SC nanomaterials, depending on the strength of the thiol-surface bonds, particle dissolution prior to assay performance can be necessary. We could demonstrate the reliability of the Ellman’s and aldrithiol assay for the quantification of surface groups on nanomaterials by ICP-OES and derived assay-specific requirements and limitations. Generally, it is strongly recommended to carefully control assay performance for new samples, components, and sample ingredients to timely identify possible interferences distorting quantification.…
Autor*innen: | Nithiya Nirmalananthan-Budau |
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Koautor*innen: | Marko Moser, Daniel GeißlerORCiD, Thomas Behnke, Ute Resch-GengerORCiD |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2018 |
Organisationseinheit der BAM: | 1 Analytische Chemie; Referenzmaterialien |
1 Analytische Chemie; Referenzmaterialien / 1.2 Biophotonik | |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Freie Schlagwörter: | Multimodal reporters; Nanoparticles; Surface chemistry; Surface functionalization |
Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
Veranstaltung: | BAM-BfR Seminar 2018 |
Veranstaltungsort: | Berlin, Germany |
Beginndatum der Veranstaltung: | 15.02.2018 |
Bemerkung: | Geburtsname von Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. - Birth name of Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 07.05.2018 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |