Park, Hoyoung Hwang, Mintai P. Lee, Jong-Wook Choi, Jonghoon Lee, Kwan Hyi 2024-01-20T12:01:49Z 2024-01-20T12:01:49Z 2021-09-05 2013-07-19 0957-4484 https://pubs.kist.re.kr/handle/201004/127863 The field of biomarker quantification has experienced a growth parallel to the discovery of new materials. In this paper, we propose an innovative system for the separation and quantification of biomarkers using a simple magnetic bead (MB)-quantum dot (QD) sandwich assay. The basis of the system lies in the interaction between histidine residues on protein G and Ni ions on QDs, and the use of imidazole to selectively detach QDs bound to target biomarkers, in effect enumerating the absolute number of biomarker units. We used C-reactive protein (CRP) as a proof-of-concept and demonstrated a detection sensitivity of 82.5 fmoles in 50 mu 1 of sample volume, a commonly used analytical volume (e.g. ELISA). Although CRP was used as a model to conduct this study, the sensitivity and simplicity of this detachable system make it a viable approach in the quantification of other target analytes. English IOP PUBLISHING LTD C-REACTIVE PROTEIN MAGNETIC MICROBEADS IMMUNOASSAYS CELLS HUMIDITY DISEASE DESIGN CANCER Harnessing immunomagnetic separation and quantum dot-based quantification capacities for the enumeration of absolute levels of biomarker Article 10.1088/0957-4484/24/28/285103 1 NANOTECHNOLOGY, v.24, no.28 NANOTECHNOLOGY 24 28 scie scopus 000320775500003 2-s2.0-84879519022 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Science & Technology - Other Topics Materials Science Physics Article C-REACTIVE PROTEIN MAGNETIC MICROBEADS IMMUNOASSAYS CELLS HUMIDITY DISEASE DESIGN CANCER