title: Multivalent interaction-based carbohydrate biosensors for signal amplification.
abstract: Multivalent interaction between boronic acids immobilized on quartz crystal microbalance (QCM) sensor surface and the carbohydrates modified Au-nanoparticle (AuNP) has been demonstrated for the development of a sensitive carbohydrate biosensor. Briefly, a boronic acid-containing polymer (boropolymer) as multivalent carbohydrate receptor was oriented immobilized on the cysteamine coated electrode through isourea bond formation. Carbohydrates were conjugated to AuNPs to generate a multivalent carbohydrates moiety to amplify the response signal. Thus, the binding of the carbohydrate conjugated AuNPs to the boropolymer surface are multivalent which could simultaneously increase the binding affinity and specificity. We systematically studied the binding between five carbohydrates conjugated AuNPs and the boropolymer. Our studies show that the associate constant (K(a)) was in the order of fucose<glucose<mannose<galactose<maltose. A linear response in the range from 23 μM to 3.83 mM was observed for mannose conjugated AuNPs and the boropolymer recognition elements, with the lower detection limit of 1.5 μM for the carbohydrate analytes. Furthermore, the multivalent binding between carbohydrates and boronic acids are reversible and allow the regeneration of boropolymer surface by using 1M acetic acid so as to sequentially capture and release the carbohydrate analytes.
authors.affiliation: Department of Chemistry, Oakland University, 2200 Squirrel Road, Rochester, MI 48309, USA.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Wang
authors.forename: Srinivas
authors.initials: S
authors.lastname: Chalagalla
authors.forename: Tiehai
authors.initials: T
authors.lastname: Li
authors.forename: Xue-Long
authors.initials: XL
authors.lastname: Sun
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Peng G
authors.initials: PG
authors.lastname: Wang
authors.forename: Xiangqun
authors.initials: X
authors.lastname: Zeng
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001897:Boronic Acids; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000737:chemistry*; D055664:Electrochemical Techniques; D006046:Gold; D053768:Metal Nanoparticles; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques
chemical_list: D001897:Boronic Acids; D002241:Carbohydrates; D011108:Polymers; D006046:Gold