論文内容の要旨

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論文内容の要旨

Chemiluminescence

（CL）

is a process of transforming chemical energy into light emission. It has been an attractive topic of intensive research over 100 years. Now it has developed to an important and powerful tool in biological and medical investigations.

CL analysis is a powerful analytical technique. It has a cheap and simple optical detection system with low background noise, low detection limit, and wide working range. It has been proven effective in rapid and sensitive measurements at ultra-trace levels.

Quantum dots （QDs, or colloidal semiconductor nanocrystals （NCs）） , have become the focus of research attention due to the unique size-dependent optical and electronic properties

，and have been widely used in recent years. Compared to fluorescent

semiconductor nanocrystals, photoluminescent carbon nanodots （C-dots） are superior in chemical stability, biocompatibility, and low toxicity.

Reactive oxygen species

（ROS）are chemically reactive molecules containing oxygen.

Examples include oxygen ions and peroxides. Recently, most research interests on ROS

氏名（本籍）周雲（中国）

専攻分野の名称博士（工学）

学位記番号工博乙第４０号学位授与の日付平成

26

年

3

月

27

日学位授与の要件学位規則第４条第２項該当

研究科・専攻工学資源学研究科（機能物質工学）

学位論文題名

Chemiluminescence Enhanced by Quantum Dots from Peroxide Reactions and Its Application in Analytical

Chemistry.

(過酸化反応を用いる量子ドットにより増強される化学発光及び

その分析化学への応用)

論文審査委員（主査）教授小川信明

（副査）教授伊藤英晃（副査）教授寺境光俊

（副査）教授久保田広志（副査）教授林金明

Akita University

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are focused on its effects on life science，medicine and environment.

In the present work, the CL of ROS originated from peroxide reactions with and without QDs and C-dots sensitizers and its analytical application were investigated.

The CL mechanism of ROS was also studied. The contents were summarized as follows:

Chapter 1 The concept, principles and the development of investigation and application of CL, ROS, QDs sensitizers were introduced.

Chapter 2 Enhanced CL of peroxomonosulfate–cobalt （II） system in the presence of dicarboxylic acids. In this work, the effects of molecular mass aliphatic dicarboxylic acids on the HSO

5＾-

Co

²⁺

CL system were investigated. It was found that the aliphatic dicarboxylic acids could enhance the CL of the HSO

5＾-

Co

²⁺

system. Moreover, the CL intensities improved regularly with the increasing of the carbon chain length of the dicarboxylic acids. The enhancement of the CL should be attributed to the formation of peroxo-diacid, which finally decomposed to the original dicarboxylic acid and singlet oxygen. The mechanism of the HSO

5＾-

Co

²⁺

-dicarboxylic acid CL system was then proposed.

Chapter 3 CL from NaClO-H

2

O

2

and enhanced by l-cysteine capped Mn-doped ZnS quantum-dots. In this work, water-soluble L-cysteine capped Mn-Doped ZnS@Si quantum-dots

（Zn-dots）, a kind of sensitizer, were synthesized. It was found that this

sensitizer could enhance CL signals emitted from interaction of NaClO with H

2

O

2

in basic medium. Experimental results demonstrated that the CL enhancement of NaClO-H

2

O

2

system originated from energy transfer processes occurred between an excited dimer singlet oxygen ((

¹

O

2

)

2

*) and Zn-dots.

Chapter 4 Carbon nanodots sensitized CL on peroxomonosulfate-sulfite-hydrochloric acid system and its analytical application. In this work, new water-soluble fluorescent carbon nanodots

（C-dots）

were prepared in a facile microwave pyrolysis approach in minutes by combining glycine and polyethylene glycol 200

（

PEG 200） . It was discovered that the prepared C-dots could dramatically enhance the CL intensity of potassium peroxymonosulfate- sodium sulfite-hydrochloric acid

（PSHA）

reactions.

Experimental results indicated that the C-dots sensitized enhancements originated from their energy transfer and electron-transfer annihilation effects on the CL system.

The C-dots sensitized CL system was successfully applied to the determination of aliphatic primary amines in real water samples with satisfactory results.

Akita University

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論文審査結果の要旨

化学発光(CL)は，化学反応によって励起された化学種が基底状態に戻る際に，エネルギーを光として放出する現象であり，

100

年にわたって，多くの研究がなされてきている．

特に，生物化学や医学の分野で非常に重要な研究分野を占めてきている．その理由は，安価で低いバックグランドノイズで検出でき，定量下限が低く，広い分析範囲を持ち，迅速に，超微量分析が可能であるからである．一方，量子ドット（QDs）やカーボンドット（C

－dots）は，近年，その分析化学的な利用も盛んであり，特に

C-dots

は，毒性が低いことで，注目されている．周氏は，過酸化反応で生じる活性酸素種（ROS）と新規に合成した

QDs

や

C-dots

を共存させ，CLを増強できることを示し，さらに，分析化学的な応用例も

示した．

第

1

章は，”General Introduction(緒言)”である．本研究の背景，既往研究，歴史，研究の目的及び論文構成について述べている．

第

2

章は，”Enhanced CL of perooxomonosulfate-cobalt(II) system in the presence of

dicarboxylic acids (ジカルボン酸存在下で増強される過硫酸―コバルト(II)系の化学発光)”

である．直鎖のジカルボン酸が

HSO

5-

-Co

²⁺系の化学発光を増強することを見つけ，ジカルボン酸の直さが長くなるにつれて，規則的に

CＬの強度が増加することも明らかにした．ま

た，酸素一重項が関与していることなどのメカニズムを明らかにした．

第

3

章は，”Cl from NaClO-H2

O

2

and enhanced by 1-cysteine capped Mn-doped ZnS quantum-dots(QDs) (NaClO-H

2

O

2 系と

1-システインでキャップした Mn

ドープ

ZnS

量子ドットによって増強される

NaClO-H

2

O

2系の化学発光)”である．この

QDs

が新規に合成され，この

QDs

が，NaClO-H2

O

2系の

CL

を増強することを初めて明らかにし，この

CL

の増強は，励起酸素一重項ダイマーと

QDs

間のエネルギー移動に起因して起こることを実験的に証明した．

第

4

章は，”

Carbon nanodots (C-dots) sensitized CL on peroxomonosulfate -sulfite-hydrochloric acid system and its analytical application (過硫酸―亜硫酸―塩酸系

の

CL

の増強とその分析化学的応用)である．グリシンとポリエチレングリコールを用いて，

新規な

C-dots

を合成し，過硫酸―亜硫酸―塩酸系の

CL

を約

30

倍以上も増強すること及び

そのメカニズムを明らかにした．また，この系を直鎖のアミン類の分析に応用し，実際の水試料の分析に使えることも明らかにした．

第

5

章は，”Conclusions(結論)”であり，博士論文全体の結論を述べている．

これらは，分析化学の分野に充分貢献する成果であり，高く評価できる．よって，本論文は，博士（工学）の学位論文として十分に価値があるものと認められる．