Colorimetric detection of UCHL1 using gold nanoparticles for rapid diagnosis of brain injury

Agarwal, S (2014) Colorimetric detection of UCHL1 using gold nanoparticles for rapid diagnosis of brain injury. Masters thesis, Indian Institute of Technology, Hyderabad.

Preview

Text
BO12M1009.pdf - Submitted Version
Download (2MB)

Abstract

Ubiquitin C-terminal hydrolase-1 (UCH-L1), an endoprotease that cleaves the specific peptide bond between the ubiquitin molecules, is released in the serum and cerebrospinal fluid (CSF) following severe brain injury. The level of UCHL1 in serum and CSF is inversely proportional to the chance of survival and therefore an important biomarker for brain injury. We developed a sensitive and accurate colorimetric assay using gold nanoparticles (30nm) based on surface plasmon resonance-dependent absorption of visible light at 520nm. Synthesising a specific ubiquitin polypeptide substrate for UCHL1 with two terminal thiol groups, we allowed gold nanoparticles to interact. This resulted blue colour aggregation of substrate polypeptide and nanoparticles with an absorption maxima of 600nm. On addition of UCHL1 to these aggregate, substrate polypeptide molecules was cleaved at the specific position and clustered gold nanoparticles became dispersed resulting the absorption maxima shifting to 520nm and changing the blue colour to red. Presently severity of brain injury is diagnosed using neuro-imaging such as CT scanning and MRI. Simple and inexpensive biochemical assay that we developed might help the physicians to quickly determine severity of the damage, monitor the progress of the treatment and ultimately predict the risk of death of individual patients.

[error in script]

IITH Creators: