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We report a biofunctionalization strategy for the assembly of catalytically active enzymes within a completely packaged bioMEMS device, through the programmed generation of electrical signals at spatially and temporally defined sites. The enzyme of a bacterial metabolic pathway, S-adenosylhomocysteine nucleosidase (Pfs), is genetically fused with a(More)
The traditional motivation for integrating biological components into microfabricated devices has been to create biosensors that meld the molecular recognition capabilities of biology with the signal processing capabilities of electronic devices. However, a different motivation is emerging; biological components are being explored to radically change how(More)
We examined the assembly of the amine-rich polysaccharide chitosan from solution onto electrode surfaces as a result of voltage bias on the electrode. Chitosan is positively charged and water soluble under mildly acidic conditions and is uncharged and insoluble under basic conditions. We observed that chitosan is deposited from acidic solution onto the(More)
The patterning of nanoparticles represents a significant obstacle in the assembly of nanoscale materials and devices. In this report, cysteine residues were genetically engineered onto the virion surface of tobacco mosaic virus (TMV), providing attachment sites for fluorescent markers. To pattern these viruses, labeled virions were partially disassembled to(More)
Hydrogels are increasingly considered for creating three-dimensional structures in miniaturized devices, yet few techniques exist for creating such hydrogel structures. We report a new approach for creating hydrogels using the amine-containing polysaccharide chitosan. Specifically, electrodes are immersed into a slightly acidic chitosan solution and a(More)
A protein's functional properties can be adjusted by conjugating it to other polymers. We used a nature-inspired route to create a protein-polysaccharide conjugate and examined the properties of this conjugate. Specifically, the enzyme tyrosinase was used to oxidize accessible tyrosine residues of the model protein green fluorescent protein (GFP). Oxidation(More)
While microcantilevers offer exciting opportunities for mechano-detection, they often suffer from limitations in either sensitivity or selectivity. To address these limitations, we electrodeposited a chitosan film onto a cantilever surface and mechano-transduced detection events through the chitosan network. Our first demonstration was the detection of(More)
The amine-containing polysaccharide chitosan was selectively deposited onto patterned gold surfaces in response to an applied voltage. Standard microfabrication techniques were used to pattern gold onto silicon wafers, and these gold patterns served as templates for the electric field directed deposition of chitosan. Experiments conducted with a(More)
We report a new approach for microfluidic optical bioanalysis that is based on the electrically driven assembly of bio-components on a transparent sidewall and the optical detection of the assembled components using planar waveguides. This allows localized electrical signals for bio-assembly and optical signals for bio-detection that can easily be applied(More)
We report facile in situ biomolecule assembly at readily addressable sites in microfluidic channels after complete fabrication and packaging of the microfluidic device. Aminopolysaccharide chitosan's pH responsive and chemically reactive properties allow electric signal-guided biomolecule assembly onto conductive inorganic surfaces from the aqueous(More)