Arrays of Dual Nanomechanical Resonators for Selective Biological Detection

• Published in: Analytical chemistry (Washington) Vol. 81; no. 6; pp. 2274 - 2279
• Main Authors: Ramos, Daniel, Arroyo-Hernández, María, Gil-Santos, Eduardo, Duy Tong, Hien, Van Rijn, Cees, Calleja, Montserrat, Tamayo, Javier
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.03.2009
• Subjects: Adsorption; Analytical chemistry; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Chemistry; Deoxyribonucleic acid; DNA; DNA - chemistry; Exact sciences and technology; Fluorescent Dyes - chemistry; General, instrumentation; Gold; Gold - chemistry; Molecular structure; Nanoparticles - chemistry; Nucleic Acid Hybridization; Silicon Compounds - chemistry; Silicon nitride; Intermolecular interaction; Gold; Thiol; DNA; Silicon nitride; DNA hybridization; Flavor; Comparative study; Nanomechanical resonator
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac8024152

Arrays of small nanomechanical resonators with dual geometry have been fabricated for sensitive biological detection. The arrays consist of silicon nitride resonating 100 nm thick cantilevers with sensing gold areas alternately placed on the free and fixed cantilever ends. The Au areas act as sensing regions as can be functionalized by means of thiol chemistry. The nanomechanical arrays provide a double flavor of the adsorbed molecules: the added mass reported by the cantilevers with the Au area at the tip and the nanoscale elasticity reported by the cantilevers with the Au area at the clamp. The devices were applied for DNA detection based on Watson−Crick pairing rules. The proposed design for nanomechanical resonators provides higher specificity for DNA sensing in comparison with conventional single cantilevers. The nanoscale elasticity induced by the DNA hybridization arises from the intermolecular interactions between the adsorbates bound to the cantilever and the surface stress.