The quest for monitoring our environment: portable arrayed biosensors

by Levi A. Gheber

at Physics Colloquium

Tue, 06 Nov 2018, 15:30
Nanotechnology institute building (#51) room 15

Abstract

Monitoring our environment for biological threats is a growing need largely unmet Currently biosensing platforms suffer from a myriad of shortcomings regarding various basic requirements which ultimately lead to the same end result: the need for trained expensive human intervention and the transport of the technologies to large facilities One of the chief shortcomings of present technologies is the size of sensing elements The smallest ones are produced by microarray technology: spots with a diameter of 100 m and separation of 300 400 m These sizes are the main reason for the fact that microarray handling requires heavy machines within well equipped laboratories with well trained personnel To harness the potential of parallel multiplexed assays and produce portable deployable multiplexed sensors a drastic reduction in sizes is required While nano biolithography techniques have the ability to fabricate structures of biomolecules as small as 40 nm the loss in Signal to Noise Ratio SNR accompanying miniaturization leads to very few examples of working biosensors of these sizes Autonomy of biosensing platforms requires vast integration of subsystems like sample collection purification amplification liquid handling read out analysis and remote transmission of results Such integration does not exist presently The vast majority of biosensing systems use some form of labeling for the detection of the bound target Labeling is opposed to the concept of continuous monitoring of target levels in a sample For this purpose label free detection methods are being developed so far with relatively poor sensitivity and specificity We are developing nano biolithography techniques1 to produce spots of sub m diameters2 3 while maintaining a high SNR aided with mathematical modeling4 We are also tackling additional factors impeding portability of arrayed biosensors by using polymeric detection elements molecularly impr inted polymers MIPs 5 for stability and regenerative pro perties detecting binding of analytes using label free surface enhanced Raman spectroscopy SERS 6 7 and other optical methods and integrating on chip polymer microlenses8 as part of the read out system and microfluidics9 10 for liquid sampling We present results from each of these discuss the complex inter dependencies between the various factors and ways to overcome some difficulties References 1 Taha H et al Protein printing with an atomic force sensing nanofountainpen Appl Phys Lett 83 1041 1043 doi:10 1063 1 1594844 2003 2 Ionescu R E Marks R S amp Gheber L A Nanolithography using protease etching of protein surfaces Nano Lett 3 1639 1642 doi:10 1021 nl034640m 2003 3 Ionescu R E Marks R S amp Gheber L A Manufacturing of nanochannels with controlled dimensions using protease nanolithography Nano Lett 5 821 827 doi:10 1021 nl0500510 2005 4 Tsarfati BarAd I Sauer U Preininger C amp Gheber L A Miniaturized protein arrays: Model and experiment Biosens Bioelectron 26 3774 3781 doi:10 1016 j bios 2011 02 030 2011 5 Belmont A S Sokuler M Haupt K amp Gheber L A Direct writing of molecularly imprinted microstructures using a nanofountain pen Appl Phys Lett 90 doi:Artn 193101 10 1063 1 2730753 2007 6 Kantarovich K Tsarfati I Gheber L A Haupt K amp Bar I Writing Droplets of Molecularly Imprinted Polymers by Nano Fountain Pen and Detecting Their Molecular Interactions by Surface Enhanced Raman Scattering Anal Chem 81 5686 5690 doi:10 1021 ac900418x 2009 7 Kantarovich K Tsarfati I Gheber L A Haupt K amp Bar I Reading microdots of a molecularly imprinted polymer by surface enhanced Raman spectroscopy Biosens Bioelectron 26 809 814 doi:10 1016 j bios 2010 06 018 2010 8 Sokuler M amp Gheber L A Nano fountain pen manufacture of polymer lenses for nano biochip applications Nano Lett 6 848 853 doi:10 1021 nl060323e 2006 9 Babu H K R R amp Gheber L A Rapid assaying of miniaturized protein microarray Se nsor Actuat B Chem 268 55 60 doi:10 1016 j snb 2018 04 074 2018 10 Babu H K R R amp Gheber L A Fluorescence based kinetic analysis of miniaturized protein microarrays Biosens Bioelectron 122 290 299 doi:https: doi org 10 1016 j bios 2018 09 051 2018 Refreshments are served at 15:15

Created on 06-11-2018 by Bar Lev, Yevgeny (ybarlev)
Updaded on 06-11-2018 by Bar Lev, Yevgeny (ybarlev)