{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T05:25:16Z","timestamp":1771305916389,"version":"3.50.1"},"reference-count":51,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2022,10,20]],"date-time":"2022-10-20T00:00:00Z","timestamp":1666224000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Social Fund","award":["09.3.3-LMT-K-712-19-0170"],"award-info":[{"award-number":["09.3.3-LMT-K-712-19-0170"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The application of antibody-functionalized quantum dots (QDs) in different areas has been widely described in the literature. However, a standard routine method for obtaining information on the conjugation efficiency of QDs with antibodies in terms of the interaction of the functionalized QDs with a specific antigen is still lacking. Herein, surface plasmon resonance (SPR) spectroscopy is proposed for this purpose. Gold-coated SPR sensor disks were modified with a self-assembled monolayer of 11-mercaptoundecanoic acid, and carbodiimide cross-linker chemistry was used to covalently immobilize the CD44 biomarker on the premodified surface (Au\/CD44). Meanwhile, QDs functionalized with amine-derivatized polyethylene glycol (PEG) (QDs-NH2) were chosen for conjugation with antibodies because of their low non-specific adsorption on the Au\/CD44 surface. Prior to conjugation, the surface binding capacity (Bmax) and equilibrium dissociation constant (KD) of the specific antibodies against CD44 (anti-CD44) were found to be 263.32 \u00b1 2.44 m\u00b0 and 1.00 \u00d7 10\u22127 \u00b1 2.29 \u00d7 10\u22129 M, respectively. QDs-NH2 and anti-CD44 were conjugated at their initial molar ratios of 1:3, 1:5, 1:10 and 1:12. SPR measurements showed that the conjugates (QDs-anti-CD44) prepared using 1:10 and 1:12 molar ratios interacted comparably with immobilized CD44 biomarkers. The equilibrium angles in the case of 10- and 12-fold concentrations of anti-CD44 were calculated to be 60.43 \u00b1 4.51 and 61.36 \u00b1 4.40 m\u00b0, respectively. This could be explained by the QDs-NH2 and anti-CD44 having a similar surface loading (about four molecules per QDs-NH2) and similar hydrodynamic diameters, which were 46.63 \u00b1 3.86 and 42.42 \u00b1 0.80 nm for the 1:10 and 1:12 ratios, respectively. An initial QDs-NH2: anti-CD44 molar ratio of 1:10 was chosen as being optimal. SPR spectroscopy proved to be the right choice for QDs-anti-CD44 conjugation optimization, and can be used for the evaluation of conjugation efficiency for other nanostructures with various bio-recognition molecules.<\/jats:p>","DOI":"10.3390\/ijms232012626","type":"journal-article","created":{"date-parts":[[2022,10,20]],"date-time":"2022-10-20T22:49:46Z","timestamp":1666306186000},"page":"12626","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Experimental Evaluation of Quantum Dots and Antibodies Conjugation by Surface Plasmon Resonance Spectroscopy"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9867-1931","authenticated-orcid":false,"given":"Anton","family":"Popov","sequence":"first","affiliation":[{"name":"Department of Immunology, State Research Institute Centre for Innovative Medicine, Santariskiu Str. 5, LT-08406 Vilnius, Lithuania"},{"name":"NanoTechnas\u2014Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Viktorija","family":"Lisyte","sequence":"additional","affiliation":[{"name":"NanoTechnas\u2014Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Asta","family":"Kausaite-Minkstimiene","sequence":"additional","affiliation":[{"name":"Department of Immunology, State Research Institute Centre for Innovative Medicine, Santariskiu Str. 5, LT-08406 Vilnius, Lithuania"},{"name":"NanoTechnas\u2014Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eiva","family":"Bernotiene","sequence":"additional","affiliation":[{"name":"Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Santariskiu Str. 5, LT-08406 Vilnius, Lithuania"},{"name":"Department of Chemistry and Bioengineering, The Faculty of Fundamental Sciences, Vilnius Gediminas Technical University, Vilnius-Tech, LT-10223 Vilnius, Lithuania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5864-0359","authenticated-orcid":false,"given":"Almira","family":"Ramanaviciene","sequence":"additional","affiliation":[{"name":"Department of Immunology, State Research Institute Centre for Innovative Medicine, Santariskiu Str. 5, LT-08406 Vilnius, Lithuania"},{"name":"NanoTechnas\u2014Center of Nanotechnology and Materials Science, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,10,20]]},"reference":[{"key":"ref_1","first-page":"eaaz8541","article-title":"Semiconductor quantum dots: Technological progress and future challenges","volume":"373","author":"Talapin","year":"2022","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"5286","DOI":"10.1021\/nn2023123","article-title":"Biofunctional Quantum Dots: Controlled Conjugation for Multiplexed Biosensors","volume":"5","author":"Hildebrandt","year":"2011","journal-title":"ACS Nano"},{"key":"ref_3","unstructured":"Ozkan, S.A., Bakirhan, N.K., and Mollarasouli, F. 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