Development of optical biosensing systems by employing smartphone-embedded electronic components
- 주제(키워드) Smartphone sensor , Optical biosensor , POCT
- 발행기관 아주대학교
- 지도교수 윤현철
- 발행년도 2016
- 학위수여년월 2016. 8
- 학위명 박사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000022976
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
The various smartphone-embedded high technical electronic elements were integrated with biological analytic principle for utilization of simple, low-cost, and user-centered biosensing platform. Currently, the high electronic components such as magnetic sensor, infra-red (IR) sensor, illumination sensor, and charge-coupled (CCD) were contained in the smart IT device. Among them, the illumination sensor and CCD camera were employed to develop the smartphone-based simple optical biosensing system. First, to demonstrate the illumination sensor-based optical biosensing principle, the immunosensing principle was integrated with an immunoblotting assay and a built-in illumination sensor to analyze an osteoarthritis marker. In the various smartphone elements, the illumination sensor sensitively responds to the external light intensity, allowing the application for a simple optical system as a signal transducer. In this study, horseradish peroxidase (HRP)-induced immunoblotting assay was employed to induce the precipitation. The precipitation-induced biosensing channel altered the light intensity according to the analyte which was registered by the illumination sensor. The ambient lights, sunlight and fluorescent, were used as light sources to minimize the composition of the developed optical sensor and increase the usability. Using this, the values of 0–10 ng/mL of urinary C-terminal telopeptide fragment of type II collagen (uCTX-II) were sensitively quantified with good reproducibility. Second, a smartphone-embedded CCD camera was integrated with the paper-based analytical device (PAD) for glucose monitoring. The smartphone-embedded CCD camera has the high technical element, enabling the acquirement of the high-resolution images. To effectively analyze the glucose, a colorimetric glucose assay method using glucose oxidase (GOx) and HRP were employed, implanting on the paper-based analytical device. To confirm the changes in optical signal intensity from the glucose assay, the resulting image was registered by a CCD camera from a smartphone. The experiment was performed in a specifically designed light-tight box mounted with smartphone. By using the developed biosensing system, various concentrations of glucose samples in PBS (0 ~ 20 mM) and human serum (5 ~ 17 mM) were simply and quantitatively analyzed within a few minutes. Third, a simple quantification principle was developed by employing the smartphone-embedded CCD camera with countable microbeads-based biochemical analysis principle for detection of CTX-II. A CCD camera on the smartphone was integrated with the simple prism, filter, and laser for realization of the minimized fluorescence microscope. To detect the biospecific immunoassay for the CTX-II, the quantum-dot (QD) particle having a maximum emission spectrum at 620 nm was employed as an optical signaling probe. The 405 nm laser was installed into the developed biosensing platform as a light source to excite the QD particle. The result images were observed and registered by smartphone-embedded CCD camera, and the immune-specific signal was quantitatively analyzed by counting the number of fluorescent microbeads from the registered images. Using the approach, the sandwich (sCTX-II) and competition (uCTX-II) assays could be immediately quantified on a single chip. The smartphone-based assay would be a promising tool for monitoring of osteoarthritis as a point-of-care testing (POCT) device. Based on these findings, I successfully established a versatile biosensing platform employing the simple utilization of smartphone-embedded high-technical electronics components which can be used for practical disease diagnosis as a POCT device.
more목차
Chapter I. General Introduction·························································1
1.1 Biosensor·······················································································2
1.2 Point-of-care testing (POCT) device···················································5
1.3 Smartphone-based biosensor···························································8
1.4 Objectives of the thesis··································································11
1.5 References···················································································14
Chapter II. Utilization of ambient light-based optical biosensing system by employing the smartphone-embedded illumination sensor·············16
Abstract···························································································17
2.1 Introduction···················································································18
2.2 Experimental section
2.2.1 Chemicals and apparatus································································22
2.2.2 Surface modification of the biosensing channel···································22
2.2.3 Fabrication of biosensing layer for uCTX-II competition immunoassay········23
2.3 Results and Discussion
2.3.1 Signal transducing principle of designed illumination sensor····················25
2.3.2 Verification of developed optical sensing principle·······························27
2.3.3 Comparison of HRP precipitating substrate·········································31
2.3.4 Illumination sensor-based urinary CTX-II analysis·······························33
2.3.5 Reactivity test for illumination sensor to the various light spectrum············39
2.3.6 Indoor light-based uCTX-II assay·····················································41
2.3.7 Sunlight-based uCTX-II assay·························································45
2.3.8 Development of mobile software for android and their application for uCTX-II assay······················································································49
2.3.9 uCTX-II analysis by using various type of smartphone····························51
2.4 References·····················································································53
Chapter III. A smartphone-based simple optical biosensing system for glucose detection by integrating the paper-based analytical device·······················55
Abstract···························································································56
3.1 Introduction···················································································57
3.2 Experimental section
3.2.1 Chemicals and apparatus································································64
3.2.2 Fabrication of microfluidic paper-based analytical device······················64
3.2.3 Manipulation of smartphone based optical detection device·······················65
3.2.4 Glucose assay using an enzymatic colorimetric assay······························65
3.3 Results and Discussion
3.3.1 Optimization of the wax-printing condition and verification of the fluid flow on PAD··········································································66
3.3.2 Implementation of the glucose sensing device to the smartphone as a signal reader·····················································································69
3.3.3 Glucose biosensing using the standard glucose-spiked buffer solutions·········74
3.3.4 Measurement of glucose concentration in human serum samples·················76
3.4 References·····················································································79
Chapter IV. Development of a smartphone-based simple quantification principle by employing the countable optical probe································81
Abstract···························································································82
4.1 Introduction··············································································83
4.2 Experimental
4.2.1 Materials and apparatus·································································89
4.2.2 Conjugation of anti-CTX-II antibody to fluoro microbeads ····················89
4.2.3 Fabrication of the fluoro-microbeads guiding chip··································92
4.2.4 uCTX-II and sCTX-II sample preparation············································94
4.2.5 Manipulation of the FMGC surface for uCTX-II and sCTX-II analysis·········94
4.2.6 Immunoassay analysis of urinary and serum CTX-II·······························95
4.2.7 Simultaneous detection of urinary and serum CTX-II··············95
4.3 Results and discussions
4.3.1 Manipulation of the fluoro-microbeads guiding chip······························97
4.3.2 Application of the fluidic control device········································101
4.3.3 Urinary CTX-II analysis employing competitive immunoassay·················104
4.3.4 Serum CTX-II analysis employing sandwich immunoassay·····················107
4.3.5 Multiple sensing of urinary and serum CTX-II·····································110
4.3.6 Smartphone-based optical signal quantification principle························113
4.3.7 Confirmation of conjugation of QD with antibody································113
4.3.8 QD-based uCTX-II analysis by employing the smartphone-embedded CCD camera···················································································116
4.4 References····················································································120
Chapter V. Conclusions and perspectives············································123
5.1 Conclusions··············································································124
5.2 Perspectives··············································································125
Summary in Korean·····································································127
Acknowledgement········································································131
