Label-Free Detection of Lectins on Carbohydrate-Modified Boron-Doped Diamond Surfaces

摘要

This paper describes the label-free detection of carbohydrate-nlectin interactions. The sensor consists of anboron-doped diamond (BDD) electrode terminated withnalkynyl surface groups, which have been functionalizednvia the CuACC (copper(I)-catalyzed azide-alkyne cycloaddition)n“click” reaction with carbohydrate analogues bearingnan azido-terminating arm. In this work, electrochemicalnimpedance spectroscopy (EIS) was used as an effectiventechnique to probe the specific interactions of the surfaceboundncarbohydrates with their complementary lectinnpartners, and the response was found to be dependentnon the relative density of sugar units immobilized on thenBDD surface. A BDD interface with 60% surface-boundnmannose showed a detection limit of ∼5 ( 0.5 nM fornLens culinaris lectin, with an affinity constant of KA )n(2.63 ( 0.5) × 106 M-1.