Fluorescent sensibility of microarrays through functionalized adhesive polydiacetylene vesicles

We present a design of 'smart' gluing interfaces with combined adhesive properties and intrinsic fluorescent sensing properties. Therefore, polymer-peptide amphiphiles with adhesive functional head-groups were coupled to a diacetylene tail and polymerized after formation of small vesicles. The vesicles were immobilized and confined into micro-arrays created by a photo-patterned perfluorinated film onto the substrate. Fluorescent properties of the vesicles in aqueous suspension were quantified to build standard curves for fluorescent intensity as a function of vesicle concentration. The fluorescent properties of surface-confined vesicles were quantified for different vesicle concentration and external normal load, by using a micro-chip reader. A combination of fluorescent microscopy and image processing was applied to demonstrate the fluorescent sensitivity of the adhesive micro-arrays as a function of vesicle composition, concentration and thermal annealing. These observations allow estimating the quality of the adhesive interface. Finally, the fluorescent sensitivity of the adhesive micro-array to mechanical solicitations such as normal load, internal shear under parallel and rotational sliding was investigated. The observations serve as a proof-of-concept for the fluorescent sensitivity of the adhesive bond as a function of the operational conditions. In future, this design may serve as an assessment tool for optimization or detection of local defects and device failure, e.g. in integrated microsystem components. (C) 2014 Elsevier B.V. All rights reserved.