Share Email Print
cover

Proceedings Paper

Enhancing enzymatic efficiency by attachment to semiconductor nanoparticles for biosensor applications
Author(s): Joyce C. Breger; Scott A. Walper; Eunkeu Oh; Kimihiro Susumu; Michael H. Stewart; Jeffrey R. Deschamps; Mario G. Ancona; Igor L. Medintz
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Nanosensors employing quantum dots (QDs) with appended biofunctional moieties offer tremendous promise for disease surveillance/diagnostics and chemical/biological threat activity. Their small size permits cell penetration and their inherent photochemical properties are well-suited for rapid, optical measurement. The effectiveness of enzymes immobilized on QDs, however, are not completely understood, hindering development of chemical/biological sensors and remediation materials. Here, we analyze enzyme effectiveness for the neutralization of a simulant nerve agent when attached to two distinctly-sized QDs. Two sizes of QDs, 525 or 625 nm, were appended with DHLA ligands to improve aqueous stability and prevent aggregation. Various molar ratios of de novo phosphotriesterase trimer (PTE3) were rapidly self-assembled via spontaneous metal coordination of the PTE oligohistidine tag onto the Zn2+-rich QD surface. PTE catalyzes the detoxification of organophosphate pesticides (e.g, paraoxon, an analog of sarin) to p-nitrophenol whose absorbance can be measured at 405 nm. The optimal ratio of PTE3 to 525 nm and 625 nm QD’s was determined to be 12 and 24, respectively. The enhanced enzyme performance in both cases is most likely due to increased enzyme-substrate interactions from improvements in enzyme orientation, enzyme density, and substrate diffusion on or near the QD. Development of these nansosensors as optical-based biosensors (e.g., within compact microfluidic devices) may greatly improve the sensitivity of conventional biological/chemical detection schemes.

Paper Details

Date Published: 13 May 2015
PDF: 7 pages
Proc. SPIE 9487, Smart Biomedical and Physiological Sensor Technology XII, 94870S (13 May 2015); doi: 10.1117/12.2180645
Show Author Affiliations
Joyce C. Breger, U.S. Naval Research Lab. (United States)
American Society for Engineering Education (United States)
Scott A. Walper, U.S. Naval Research Lab. (United States)
Eunkeu Oh, U.S. Naval Research Lab. (United States)
Sotera Defense Solutions, Inc. (United States)
Kimihiro Susumu, U.S. Naval Research Lab. (United States)
Sotera Defense Solutions, Inc. (United States)
Michael H. Stewart, U.S. Naval Research Lab. (United States)
Jeffrey R. Deschamps, U.S. Naval Research Lab. (United States)
Mario G. Ancona, U.S. Naval Research Lab. (United States)
Igor L. Medintz, U.S. Naval Research Lab. (United States)


Published in SPIE Proceedings Vol. 9487:
Smart Biomedical and Physiological Sensor Technology XII
Brian M. Cullum; Eric S. McLamore, Editor(s)

© SPIE. Terms of Use
Back to Top