Nanostructured Microcantilevers with Functionalized Cyclodextrin Receptor Phases:  Self-Assembled Monolayers and Vapor-Deposited Films

Abstract

It is shown that the performance of microcantilver-based chemical sensors in a liquid environment is affected by altering cantilever surface morphology and receptor phase type and thickness. Self-assembled monolayers of thiolated beta-cyclodextrin (HM-beta-CD) and thin films of vapor-deposited heptakis (2,3-O-diacetyl-6-O-tertbutyl-dimethylsilyl)-beta-cyclodextrin (HDATB-beta-CD) were studied on smooth and nanostructured (dealloyed) gold-coated microcantilever surfaces. The dealloyed surface contains nanometer-sized features that enhance the transduction of molecular recognition events into cantilever response, as well as increase film stability for thicker films. Improvements in the limits of detection of the compound 2,3-dihydroxynaphthalene as great as 2 orders of magnitude have been achieved by manipulating surface morphology and film thickness. The observed response factors for the analytes studied varied from 0.02-604 nm/ppm, as determined by cantilever deflection. In general, calibration plots for the analytes were linear up to several hundred nanometers in cantilever deflections.

Impression creep behaviour of magnesium alloy-based hybrid composites in the longitudinal direction

“…So, from the commercial point of view, the use of the hybrid composites, replacing small volume fraction of expensive Saffil short fi-bres by cheap SiC particulates, is beneficial. The short fibre reinforced Mg-MMCs generally increase the creep resistance [18,50] by two different mechanisms [51][52][53][54][55][56][57][58]. First way is the load transfer effect in which part of the external load is carried by the reinforcement.…”

Peer Reviewed: Microcantilever Transducers: A new Approach in Sensor Technology

“…The flow of liquids past cantilever sensors can give rise to noise or drift arising from such variables as flow rate and pressure. Intelligently designed flow cells can minimize noise, and using differential arrangements (separate sample and reference cantilevers) can reduce noise and drift (15,33,34). Figure 4 demonstrates that a significant improvement in baseline stability to liquid-flow changes is possible when a single-beam-cantilever optical arrangement with dc output is replaced by a dual-beam-cantilever arrangement with ac output.…”

Capillary Electrophoresis - Optical Detection Systems

“…We have other support and work with a group at Oak Ridge National Laboratory toward the development of microcantilever (MC)-based micro-electro-mechanical-systems (MEMS) for sensing of chemicals. [ 14,17,18,24] We recognized that certain of the molecular recognition cavitands (CDs) we employ for chemical separations and CE-SERS work should be useful reagents to impart selectivity to these MEMS devices. [l7,20] In particular, the mecapto compounds (see 8 in Fig.…”