Iron oxide/gold core/shell nanoparticles for ultrasensitive detection of carbohydrate-protein interactions.
Changes in the expression of cell surface glycan are often associated with malignant metastasis. The expression level may be dramatically enhanced during tumor progression. A highly sensitive assay that is capable of detecting low levels of cancer-associated carbohydrate antigens can be a powerful tool for early diagnosis. In this work, an ultrasensitive glycans array using iron oxide/gold core/shell nanoparticles conjugated with antibodies or proteins is developed. A magnetic field is applied to quickly bring nanoparticle labeled proteins or antibodies from a solution to an array of carbohydrates immobilized on glass slides and to help them to encounter the carbohydrates at very low concentration. The gold shell provides a well established platform for conjugation of biomolecules. Well-defined recognition systems, namely, mannose derivatives (Man1, Man4, and Man9) with a mannose binding lectin (Concanavalin A) and a stage-specific embryonic antigens-3 (SSEA-3) with a monoclonal antibody (anti-SSEA-3) were chosen to establish this detection tool. Array systems were conducted to determine their surface dissociation constant (K(D,surface)) and their binding specificity for qualitative and quantitative analysis of carbohydrate-protein and carbohydrate-antibody interactions. When coupled with a signal amplification method based on nanoparticle-promoted reduction of silver, the sensitivity of an iron oxide/gold core/shell nanoparticle-based assay reached to subattomole level in carbohydrate detection.
Liang
Chi-Hui
CH
The Genomics Research Center, Academia Sinica, Taipei, 115 Taiwan.
Wang
Cheng-Chi
CC
Lin
Yu-Chen
YC
Chen
Chung-Hsuan
CH
Wong
Chi-Huey
CH
Wu
Chung-Yi
CY
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000378:metabolism; D002241:Carbohydrates / Q000032:analysis* / Q000737:chemistry; D003208:Concanavalin A / Q000737:chemistry / Q000378:metabolism; D005290:Ferric Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D046228:Microarray Analysis / Q000379:methods*; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D002241:Carbohydrates; D005290:Ferric Compounds; D011506:Proteins; D003208:Concanavalin A; C000499:ferric oxide; D006046:Gold