1 research outputs found
Localized Three-Dimensional Functionalization of Bionanoreceptors on High-Density Micropillar Arrays via Electrowetting
In this work, we
introduce an electrowetting-assisted 3-D biofabrication
process allowing both complete and localized functionalization of
bionanoreceptors onto densely arranged 3-D microstructures. The integration
of biomaterials with 3-D microdevice components offers exciting opportunities
for communities developing miniature bioelectronics with enhanced
performance and advanced modes of operation. However, most biological
materials are stable only in properly conditioned aqueous solutions,
thus the water-repellent properties exhibited by densely arranged
micro/nanostructures (widely known as the Cassie–Baxter state)
represent a significant challenge to biomaterial integration. Here,
we first investigate such potential limitations using cysteine-modified
tobacco mosaic virus (TMV1cys) as a model bionanoreceptor and a set
of Au-coated Si-micropillar arrays (μPAs) of varying densities.
Furthermore, we introduce a novel biofabrication system adopting electrowetting
principles for the controlled localization of TMV1cys bionanoreptors
on densely arranged μPAs. Contact angle analysis and SEM characterizations
provide clear evidence to indicate structural hydrophobicity as a
key limiting factor for 3-D biofunctionalization and for electrowetting
as an effective method to overcome this limitation. The successful
3-D biofabrication is confirmed using SEM and fluorescence microscopy
that show spatially controlled and uniform assemblies of TMV1cys on
μPAs. The increased density of TMV1cys per device footprint
produces a 7-fold increase in fluorescence intensity attributed to
the μPAs when compared to similar assemblies on planar substrates.
Combined, this work demonstrates the potential of electrowetting as
a unique enabling solution for the controlled and efficient biofabrication
of 3-D-patterned micro/nanodomains