title: Highly sensitive gold nanoparticles biosensor chips modified with a self-assembled bilayer for detection of Con A.
abstract: In this paper, an improved method for detection of Concanavalin A (Con A) with label-free optical biosensors is reported. 1-Dodecanethiol (DDT) was self-assembled onto gold nanoparticles which were deposited on glass slides, and then glycolipid molecules were inserted into dodecanethiol by physical interactions only. The recognition between Con A and carbohydrate was observed by UV-vis spectrophotometry. The absorption spectrum shifted when Con A was bound to the sugar residues of glycolipids immobilized onto nanogold slides, while almost no spectrum change was observed when another nonspecific protein molecule met the nanogold slides. The self-assembled bilayer on nanogold substrates had very high sensitivity for Con A, the minimum detection concentration of Con A can be down to 0.1 nM. In addition to the ultra sensitivity for investigating carbohydrate-lectin interaction, the self-assembled bilayer structure, is expected to replace many receptors which require time-consuming organic syntheses for the fixation to the transducer. The simplicity and sensitivity of this biosensor architecture once again show the prospect of nanogold application in biosensor.
authors.affiliation: Key Laboratory of Colloid and Interface Science, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Science, Beijing 100080, PR China.
authors.forename: Caixin
authors.initials: C
authors.lastname: Guo
authors.forename: Paul
authors.initials: P
authors.lastname: Boullanger
authors.forename: Long
authors.initials: L
authors.lastname: Jiang
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003208:Concanavalin A / Q000032:analysis*; D006017:Glycolipids; D017979:Gold Colloid; D053758:Nanoparticles; D012680:Sensitivity and Specificity; D013438:Sulfhydryl Compounds
chemical_list: D006017:Glycolipids; D017979:Gold Colloid; D013438:Sulfhydryl Compounds; D003208:Concanavalin A; C013976:dodecylmercaptan