Composite electrodes for hot electron-induced electrochemiluminescence applications

Kalle Salminen

Composite electrodes for hot electron-induced electrochemiluminescence applications

Julkaisun otsikon käännös: Komposiittielektrodien hyödyntäminen kuumien elektronien aikaansaamassa elektrokemiluminesenssissa

Kalle Salminen

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Suurin osa väitöskirjatyöstä keskittyi erilaisten hiilimusta-pohjaisten komposiittielektrodien valmistamiseen hyödyntämiseen kuumien elektroninen aikaansaamassa elektrokemiluminesenssissa (HECL). HECL on analyyttinen menetelmä, joka perustuu hydratoituneiden elektronien sähkökemialliseen tuottamiseen vesiliuoksissa. Näiden elektronien suuri energia mahdollistaa lukuisten luminoforien virittämisen nestefaasissa ja emittoituvaa valoa voidaan hyödyntää analytiikassa erilaisin tavoin. HECL eroaa muista elektrokemiluminesenssimenetelmistä siinä, että kaikki virittymiseen liittyvät reaktiot tapahtuvat liuosfaasissa. Menetelmän etuihin lukeutuu tarkkuus sekä yksinkertainen mittalaitteisto verrattuna muihin elektrokemiluminesenssimenetelmiin. Johtuen vedynkehityksestä on hydratoituneiden elektronien sähkökemiallinen tuottaminen haastavaa. Esimerkiksi elohopea-elektrodilla joka on tunnettu suuresta vedynkehityksen ylipotentiaalista ei havaita odotetun kaltaista muutosta potentiaali-virta kuvaajissa. HECL mittaukset onkin aikaisemmin tehty eristeohutkalvon peittämillä metalli- tai puolijohdelektrodeilla. Tyypillisimpiä työelektrodeja ovat olleet oksidipäällysteiset alumiini ja pii. Aiempien materiaalien suurimpia ongelmia on ollut elektrodien valmistamiseen liittyvät tekijät. Hydratoituneiden elektronien luominen, ja tätä kautta havaittavan valon intensiteetti, on äärimmäisen riippuvaista ohutkalvon paksuudesta. Jopa parin nanometrin vaihtelu kalvopaksuudessa aiheuttaa suuria muutoksia havaitussa valomäärässä. HECL:n tärkein käyttökohde on ollut immunomääritykset, joissa työelektrodin pinta päällystetään vasta-aineilla. Näissä sovelluskohteissa elektrodit ovat kertakäyttöisiä, minkä takia puhdastiloja edellyttävät elektrodit ovat yksi suurimmista pullonkauloista menetelmän kaupallistamiselle. Eräs tapa ratkaista edellä esitetyt ongelmat on komposiittimateriaalien hyödyntäminen elektrodimateriaalina. Tässä työssä tutkitut komposiittielektrodit koostuivat polymeerimatriisista sekä sähköä johtavista hiilimustapartikkeleista. Näiden elektrodien toimivuus osoittautui erinomaiseksi: HECL signaalin hajonta saman valmistuserän elektrodien välillä oli alhaista, taustaemissio lähes olematonta ja HECL signaalin suuruus verrattavissa aiempiin elektrodimateriaaleihin. Johdepartikkelien läsnäolo mahdollistaa elektrodien valmistamisen esimerkiksi silkkipainomenetelmällä. Nämä alustavat kokeet osoittivat, että hydratoituneiden elektronien luominen sähköisesti on huomattavasti helpompaa kuin aikaisemmin on ajateltu.

Julkaisun otsikon käännös	Komposiittielektrodien hyödyntäminen kuumien elektronien aikaansaamassa elektrokemiluminesenssissa
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Kulmala, Sakari, Vastuuprofessori
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-8852-5
Sähköinen ISBN	978-952-60-8853-2
Tila	Julkaistu - 2019
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

hydratoitunut elektroni
komposiittielektrodit
immunomääritykset

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-8853-2

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@phdthesis{a916363ddce940dbbdf45df548c4bead,

title = "Composite electrodes for hot electron-induced electrochemiluminescence applications",

abstract = "The present thesis primarily focuses on the applicability of carbon black containing composite electrodes for hot electron-induced electrochemiluminescence (HECL) applications. HECL is an analytical method that utilizes electrogenerated hydrated electrons as mediators in chemical reactions that lead to luminescence, typically in the visible part of the electromagnetic spectrum. The high energy of hydrated electrons makes them the ideal chemical species for chemiluminescence reactions taking place in the liquid phase. The quantitative analysis of chemical species is typically performed by labelling the analytes with a suitable luminophore. The main advantages of HECL are sensitivity, accuracy and low-cost instrumentation when compared to similar, chemiluminescence based, methods. The generation of hydrated electrons via electrochemical means is complicated by the narrow electrochemical window of water. There are no expected changes in the current-potential curves at high cathodic potentials. The only observed process, even at mercury electrodes, is hydrogen evolution. To circumvent problems related to the hydrogen evolution, the HECL experiments are typically carried out at insulating thin-film covered electrodes such as aluminum and silicon. The energy of the electrons at the electrode/electrolyte-interface at these materials is sensitive to the thickness of the insulating film. A variation of a few nanometers in the film thickness leads to noteworthy changes in the observed HECL emission intensity. The main applications of HECL lie in the healthcare sector where high accuracy is demanded from the analytical methods. Consequently, the traditional electrodes utilized in HECL applications have to be manufactured in a clean room environment by thin-film deposition techniques that increases the cost to run a single test. The approach taken in the present study for decreasing the total electrode cost is the use of novel conductive composite materials as the working electrode. The introduction of conductive carbon black particles to a polymer (e.g. polystyrene) matrix makes it possible to manufacture electrodes by e.g. screen-printing method. The results presented in this thesis show that the conductive carbon containing composite materials are well suited for HECL applications. The reproducibility of HECL signal between electrodes is high and the detection limits are practically equal to what is achieved with conventional electrode materials. These pioneering studies show that the electrochemical generation of hydrated electrons is considerably easier than previously thought.",

keywords = "HECL, hydrated electrons, composite electrodes, immunoassays, hydratoitunut elektroni, komposiittielektrodit, immunom{\"a}{\"a}ritykset, HECL, hydrated electrons, composite electrodes, immunoassays",

author = "Kalle Salminen",

year = "2019",

language = "English",

isbn = "978-952-60-8852-5",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "223",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Composite electrodes for hot electron-induced electrochemiluminescence applications

AU - Salminen, Kalle

PY - 2019

Y1 - 2019

N2 - The present thesis primarily focuses on the applicability of carbon black containing composite electrodes for hot electron-induced electrochemiluminescence (HECL) applications. HECL is an analytical method that utilizes electrogenerated hydrated electrons as mediators in chemical reactions that lead to luminescence, typically in the visible part of the electromagnetic spectrum. The high energy of hydrated electrons makes them the ideal chemical species for chemiluminescence reactions taking place in the liquid phase. The quantitative analysis of chemical species is typically performed by labelling the analytes with a suitable luminophore. The main advantages of HECL are sensitivity, accuracy and low-cost instrumentation when compared to similar, chemiluminescence based, methods. The generation of hydrated electrons via electrochemical means is complicated by the narrow electrochemical window of water. There are no expected changes in the current-potential curves at high cathodic potentials. The only observed process, even at mercury electrodes, is hydrogen evolution. To circumvent problems related to the hydrogen evolution, the HECL experiments are typically carried out at insulating thin-film covered electrodes such as aluminum and silicon. The energy of the electrons at the electrode/electrolyte-interface at these materials is sensitive to the thickness of the insulating film. A variation of a few nanometers in the film thickness leads to noteworthy changes in the observed HECL emission intensity. The main applications of HECL lie in the healthcare sector where high accuracy is demanded from the analytical methods. Consequently, the traditional electrodes utilized in HECL applications have to be manufactured in a clean room environment by thin-film deposition techniques that increases the cost to run a single test. The approach taken in the present study for decreasing the total electrode cost is the use of novel conductive composite materials as the working electrode. The introduction of conductive carbon black particles to a polymer (e.g. polystyrene) matrix makes it possible to manufacture electrodes by e.g. screen-printing method. The results presented in this thesis show that the conductive carbon containing composite materials are well suited for HECL applications. The reproducibility of HECL signal between electrodes is high and the detection limits are practically equal to what is achieved with conventional electrode materials. These pioneering studies show that the electrochemical generation of hydrated electrons is considerably easier than previously thought.

AB - The present thesis primarily focuses on the applicability of carbon black containing composite electrodes for hot electron-induced electrochemiluminescence (HECL) applications. HECL is an analytical method that utilizes electrogenerated hydrated electrons as mediators in chemical reactions that lead to luminescence, typically in the visible part of the electromagnetic spectrum. The high energy of hydrated electrons makes them the ideal chemical species for chemiluminescence reactions taking place in the liquid phase. The quantitative analysis of chemical species is typically performed by labelling the analytes with a suitable luminophore. The main advantages of HECL are sensitivity, accuracy and low-cost instrumentation when compared to similar, chemiluminescence based, methods. The generation of hydrated electrons via electrochemical means is complicated by the narrow electrochemical window of water. There are no expected changes in the current-potential curves at high cathodic potentials. The only observed process, even at mercury electrodes, is hydrogen evolution. To circumvent problems related to the hydrogen evolution, the HECL experiments are typically carried out at insulating thin-film covered electrodes such as aluminum and silicon. The energy of the electrons at the electrode/electrolyte-interface at these materials is sensitive to the thickness of the insulating film. A variation of a few nanometers in the film thickness leads to noteworthy changes in the observed HECL emission intensity. The main applications of HECL lie in the healthcare sector where high accuracy is demanded from the analytical methods. Consequently, the traditional electrodes utilized in HECL applications have to be manufactured in a clean room environment by thin-film deposition techniques that increases the cost to run a single test. The approach taken in the present study for decreasing the total electrode cost is the use of novel conductive composite materials as the working electrode. The introduction of conductive carbon black particles to a polymer (e.g. polystyrene) matrix makes it possible to manufacture electrodes by e.g. screen-printing method. The results presented in this thesis show that the conductive carbon containing composite materials are well suited for HECL applications. The reproducibility of HECL signal between electrodes is high and the detection limits are practically equal to what is achieved with conventional electrode materials. These pioneering studies show that the electrochemical generation of hydrated electrons is considerably easier than previously thought.

KW - HECL

KW - hydrated electrons

KW - composite electrodes

KW - immunoassays

KW - hydratoitunut elektroni

KW - komposiittielektrodit

KW - immunomääritykset

KW - HECL

KW - hydrated electrons

KW - composite electrodes

KW - immunoassays

M3 - Doctoral Thesis

SN - 978-952-60-8852-5

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Composite electrodes for hot electron-induced electrochemiluminescence applications

Abstrakti

Tutkimusalat

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