Sensor Array Composed of “Clicked” Individual Microcantilever Chips



A simple technique is described to functionalize a small library of microcantilever (MC) chips presenting varied headgroups. A generic azide monolayer, bound to the MC surface, can be coupled with various alkynes using efficient "click" chemistry. This method is compatible with many functional groups, and novel headgroups are introduced on the MC surface by means of alkynes synthesized via a one-step reaction. The surface "click" reaction reduces greatly the effort that would be required to synthesize and purify the corresponding functional thiols. This technique represents a convenient complementary tool for Phase-Shifting Interferometric Microscopy (PSIM) read-out that has been developed in our group. The affinity of these surface coatings towards different solvents can be estimated by measuring the deflection of the cantilevers. A proof-of-concept sensor composed of four individual MC chips presenting different headgroups can unambiguously discriminate the fingerprint response of a nerve-gas simulant from other solvent vapors.