Elektrogenerisana hemiluminiscencija: ispitivanje mehanizma i njena primena u bioanalitici
Electrogenerated chemiluminescence: from mechanistic insights to bioanalytical applications
Metapodaci
Prikaz svih podataka o disertacijiSažetak
U okviru ove doktorske disertacije ispitana je elektrogenerisana hemiluminiscencija (eng.
Electrogenerated chemiluminiscence - ECL) kao i razvoj novih ECL sistema za bioanalitičku
primenu. ECL je metoda u kojoj se analitički signal u vidu luminiscentnog zračenja, dobija
putem elektrohemijske reakcije indukovane na površini elektorde. ECL omogućava veoma
preciznu detekciju u subpikomolarnim opsegu koncentracija sa gotovo nultim pozadinskim
signalom. Direktno optičko očitavanje može se izvršiti veoma jednostavno pomoću
fotomultiplikatorskih cevi (eng. photomultiplier tube - PMT) ili jeftinih CCD (eng. charge
coupled device - CCD) kamera. Zbog toga se ECL može lako kombinovati sa drugim
tehnologijama kao što su mikrofluidni sistemi i kapilarna elektroforeza u cilju dobijanja
kompletnog sistema za detekciju. ECL detekcija se široko koristi u komercijalizovanim
sistemima. Ova teza ima za cilj proučavanje osnovnih ECL procesa kao i razvoj inovativnih
ECL sistema za bioanalitičku primenu.
Prv...o poglavlje je posvećeno opštim principima ECL–a. Dva različita mehanizma za generisanje
ECL-a (anihilacija i ECL pomoću koreaktanata (eng. co-reactant)) su objašnjeni do detalja.
Najčešće korišćene ECL luminofore, bazirane na kompleksima rutenijuma, kao i sve vrste
korektanata, su takođe opisane. Na kraju, glavne primene elektrohemijske luminiscencije su
ukratko prikazane.
U drugom poglavlju, proučavani su ECL mehanizmi zastupljeni u imunotestovima u kojima su
platforme za ECL detekciju bazirane na česticama mikrometarskih dimenzija. Ispitan je učinak
različitih ECL mehanizama na ukupan intenzitet emitovanog ECL signala.
Spektroelektrohemija i ECL snimanje su kombinovani za posmatranje generisanja ECL na
nivou jedne mikrosfere, funkcionalizovane kompleksom rutenijuma sa dva koreaktanta,
pomoću prostornog mapiranja ECL reaktivnosti. Ovaj novi pristup snimanja ECL signala pruža
uvid u ECL mehanističke rute koji omogućavaju izuzetno visoku osetljivost komercializovanim
biotestovima baziranim na korisćenju mikrosfera/mikroperli.
Treće poglavlje govori o elektrohemijskim osobinama nanoelektroda (eng. nanoelectrode
ensembles - NEEs), i najnovijem napretku na polju njihove pirmene u bioelektroanalitičkoj
hemiji. Elektrohemijske osobine koje čine NEEs veoma korisnim u razvoju hemijskih...
Electrogenerated chemiluminiscence (ECL) is a process which emits luminiscent signals by
converting electrochemical energy into radiative energy. It offers very sensitive detection of
sub-picomolar concentrations with an extremely large dynamic range, greater than six orders
of magnitude and almost zero background signal. The direct optical readout can be performed
just with a photomultiplier tube (PMT) or inexpensive CCD cameras and therefore, easily
combined with other technologies such as microfluidics and capillary electrophoresis to obtain
complete detection systems. ECL detection is widely used in commercialized systems with an
increasing trend. The present thesis is aimed at studying the fundamental ECL process and at
developing new ECL systems for original bioanalytical applications.
Chapter one is dedicated to the general principles of ECL. Two different pathways to generate
ECL, annihilation and co-reactant ECL, are explained in details. The most used ECL
luminophores, based ...on ruthenium complexes, and co-reactants are also presented. In the last
part of this chapter, the principal applications of ECL are briefly described.
In the second chapter, the study of ECL mechanisms used in bead-based immunoassays and
their influence on ECL emission were investigated. Spectroelectrochemistry and ECL imaging
was combined to observe the ECL generation from a single micro-bead, functionalized with
ruthenium complex with two efficient co-reactants, by mapping the ECL reactivity in space.
This new imaging approach provides insights into the ECL mechanistic route operating in such
a commercialized bead-based bioassays and its extremely high sensitivity.
Chapter 3 addresses the electrochemical properties of nanoelectrode ensembles and arrays
(NEEs) with recent advances in bioelectroanalytical applications. The electrochemical
characteristic that makes the NEEs very useful in the development of chemical nanosensors is
the dramatic lowering of capacitive currents (that are the largest component of the noise, or
more properly the background signal of voltammetric measurements) allowing very sensitive
detection of analytes of interest. Exploiting both gold NEEs as a sensor platform and generation
of ECL at low oxidation potentials, a new sensitive and specific ECL immunosensor for
diagnosis of celiac disease (CD) will be presented.
In the last chapter, principles of bipolar electrochemistry (BE) will be presented. This concept
has been recently used to control the motion of autonomous microswimmers, breaking the
symmetry on the surface of this conductive objects in a wireless manner. The strategy to trigger
the motion relies on the generation and release of bubbles and was used for translation, rotation
and levitation and it will be described in details. We will present the integration of ECL light...