Title

Multivalent Interaction-based Carbohydrate Biosensors for Signal Amplification

Document Type

Article

Publication Date

11-15-2010

Publication Title

Biosensors and Bioelectronics

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 (Ka) 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 1 M acetic acid so as to sequentially capture and release the carbohydrate analytes.

Comments

This work was partly support by NIH (EB000672, XQZ), Oakland
University Research Excellent funds (XQZ). American Health
Assistance Foundation (AHAF-H2007027, XLS) and Cleveland State
University Faculty Research Development Grant (XLS). Wei Zhao
thanks the National Natural Science Foundation of China (Grant
No. 20802037) for financial support.

DOI

10.1016/j.bios.2010.08.025

Volume

26

Issue

3