?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F11851%2F&rft.title=Metal+ion+and+pH+Sensors+based+on+Carbon+Nanotubes%0D%0A&rft.creator=Gou%2C+Pingping&rft.description=The+sensitive+and+selective+detection+of+metal+ions+and+pH+levels+is+important+in+environmental+and+biomedical+applications.+Conventional+methods+are+limited+in+their+potential+due+to+high+cost%2C+big+size%2C+and+lack+of+portability.+A+new+system+incorporating+single-walled+carbon+nanotubes+(SWNTs)+modified+with+polymers+or+proteins+has+been+developed+to+create+a+cost-effective%2C+easy-to-use+metal+ion%2FpH+sensing+platform.+This+system+utilized+SWNTs+modified+with+metal+ion%2FpH+sensitive+materials+because+pristine+SWNTs+are+only+sensitive+to+high+concentrations+of+metal+ions+(%3E+1+mM)%2C+and+strong+base+(pH+%3E+12)+or+acid+(pH+%3C+2)%2C+and+lack+selectivity+as+well.+%0D%0AThis+work+uses+noncovalent+functionalization+approaches+to+chemically+modify+SWNTs+because+noncovalent+modifications+do+not+disrupt+SWNT+electronic+properties.+When+the+modified-SWNT+system+encounters+metal+ions+or+pH+solutions%2C+the+alteration+in+modified+layers%2C+such+as+conformational+change+or+charge+transfer%2C+initiates+signal+transduction+processes%2C+thus+changing+the+electrical+and+optical+properties+of+the+underlying+SWNTs.+The+properties+of+modified+SWNTs+were+characterized+by+a+variety+of+techniques+including+optical+spectroscopy%2C+and+electrical+transport+measurements+in+solid+state+or+liquid+state%2C+through+which+the+transduction+mechanism+of+the+system+was+investigated.%0D%0AThe+modified+SWNT-based+metal+ion%2FpH+sensors+offer+promise+in+applications+and+provide+a+platform+for+fundamental+understanding+of+the+transduction+mechanism+that+help+us+to+develop+better+chemical+sensors+in+the+future.%0D%0A&rft.date=2012-06-18&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F11851%2F1%2Fpingping_gou_ETD_2012_2.pdf&rft.identifier=++Gou%2C+Pingping++(2012)+Metal+ion+and+pH+Sensors+based+on+Carbon+Nanotubes.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++