Graduation Year

2014

Document Type

Thesis

Degree

M.S.C.H.

Degree Granting Department

Chemical Engineering

Major Professor

Venkat Bhethanabotla, Ph.D.

Committee Member

Robert Frisina, Ph.D.

Committee Member

Byeong Cha, Ph.D.

Keywords

bioassay, immunofluorescence, Micro-mixing, nanoparticles, removal

Abstract

Immunofluorescence assays are capable of both detecting the amount of a protein and the location of the protein within a cell or tissue section. Unfortunately, the traditional technique is not capable of detecting concentrations on the nanoscale. Also, the technique suffers from non-specific attachment, which can cause false-positives, as well as photobleaching when detecting lower concentrations is attempted. There is also a time constraint problem since the technique can take from many hours to a few days in some cases.

In this work, metal-enhanced fluorescence (MEF) is used to lower the detection limit and reduce photobleaching. Unfortunately, MEF also increases the intensity of non-specifically bound proteins (NSBPs). Therefore, a surface acoustic wave (SAW) device is used to remove the more weakly bound NSBPs. Previously, this has been shown on lithium niobate, but it is used with a quartz substrate in this work. The SAW device is also used to cause micro-mixing which speeds the process up significantly.

In this research, it was found that silver nanocubes can lower the detection limit down to below 1 ng/mL. Quartz SAW devices are shown to remove NSBPs at a power of 10 mW applied for five minutes. Micro-mixing is shown to be improved by a factor of six at 10 mW for 10 minutes by saturating the antibody used in this research, which takes 1 hour without micro-mixing. Finally, all three components are combined. In this work, the whole device is used to detect 50 ng/mL. After micro-mixing, the intensity is the same as with MEF, and, after removal, it has been lowered by 7 a.u.

Download

Share

COinS