Segregation of Micrometer-Dimension Biosensor Elements on a Variety of Substrate Surfaces

Abstract

With the rapid development of micro total analysis systems and sensitive biosensing technologies, it is often desirable to immobilize biomolecules to small areas of surfaces other than silicon. To this end, photolithographic techniques were used to derivatize micrometer-sized, spatially segregated biosensing elements on several different substrate surfaces. Both an interference pattern and a dynamic confocal patterning apparatus were used to control the dimensions and positions of immobilized regions. In both of these methods, a UV laser was used to initiate attachment of a photoactive biotin molecule to the substrate surfaces. Once biotin was attached to a substrate, biotin/avidin/biotin chemistry was used to attach fluorescently labeled or nonlabeled avidin and biotinylated sensing elements such as biotinylated antibodies. Dimensions of 2-10 microm were achievable with these methods. A wide variety of materials, including glassy carbon, quartz, acrylic, polystyrene, acetonitrile-butadiene-styrene, polycarbonate, and poly(dimethylsiloxane), were used as substrates. Nitrene- and carbene-generating photolinkers were investigated to achieve the most homogeneous films. These techniques were applied to create a prototype microfluidic sensor device that was used to separate fluorescently labeled secondary antibodies.

Covalent modification of graphitic carbon substrates by non-electrochemical methods

“…On the other hand, the carbene generated photolytically from diazirines can insert into C-C and C=C bonds and hence is expected to react with high yield at carbon surfaces. Using a (trifluoromethyl)diazirine derivative of biotin and their maskless photolithography methods, Kuhr and co-workers obtained a significantly more homogeneous surface coverage of immobilized biotin than when using photobiotin, confirming that carbenegenerating species are a better choice than nitrene-generating species for photografting reactions at graphitic carbons [81].…”

“…Kuhr and co-workers have developed this approach for covalently grafting biotin to graphitic carbon surfaces [79,80,81,82].…”

Biosensors for environmental pollutants and food contaminants

“…Tamanaha et al presented a new macro-microfluidics hybrid technology for chip-scale biosensors [195] and emphasized the ease of fabrication and integration in comparison to standard microfabrication technologies. Brooks et al developed a microsensor in which antibodies were discretely immobilized on a variety of surfaces, thereby ensuring a segregation of the biorecognition elements [196]. Arakelian et al investigated the influence of the external environment on microbiosensor performances [197], and Xie et al reviewed the use of micro-thermal transducers and mini-channel and multi-channel systems [198].…”

Addressable Protein Patterning via Switchable Superhydrophobic Microarrays

“…[1,2] Several techniques have been demonstrated as being capable of "writing" or "printing" biomolecules with a very high degree of spatial control, including dip-pen lithography, [3] nanopipetting, [4] inkjet printing, [5] photolithography, [6][7][8] microcontact printing, [9,10] etc. Serial writing techniques provide individual addressability whereas parallel printing processes offer easy and fast protein patterning.…”