title: Theoretical modeling and experimental validation of surface stress in thrombin aptasensor.
abstract: Adsorption of target molecules on the immobilized microcantilever surface produced beam displacement due to the differential surface stress generated between the immobilized and non-immobilized surface. Surface stress is caused by the intermolecular forces between the molecules. Van der Waals, electrostatic forces, hydrogen bonding, hydrophobic effect and steric hindrance are some of the intermolecular forces involved. A theoretical framework describing the adsorption-induced microcantilever displacement is derived in this paper. Experimental displacement of thrombin aptamer-thrombin interactions was carried out. The relation between the electrostatic interactions involved between adsorbates (thrombin) as well as adsorbates and substrates (thrombin aptamer) and the microcantilever beam displacement utilizing the proposed mathematical model was quantified and compared to the experimental value. This exercise is important to aid the designers in microcantilever sensing performance optimization.
authors.forename: Yang Choon
authors.initials: YC
authors.lastname: Lim
authors.forename: Abbas Z
authors.initials: AZ
authors.lastname: Kouzani
authors.forename: Akif
authors.initials: A
authors.lastname: Kaynak
authors.forename: Xiujuan J
authors.initials: XJ
authors.lastname: Dai
authors.forename: Guy
authors.initials: G
authors.lastname: Littlefair
authors.forename: Wei
authors.initials: W
authors.lastname: Duan
mesh_terms: D000327:Adsorption; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003198:Computer Simulation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D008956:Models, Chemical; D008958:Models, Molecular; D013314:Stress, Mechanical; D013500:Surface Tension; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry* / Q000235:genetics
chemical_list: D052157:Aptamers, Nucleotide; D013917:Thrombin