Luận án tiến sĩ: Cảm biến hóa học thế hệ mới - Elizabeth Tehan

NEW GENERATION CHEMICAL SENSORS AND SENSOR SYSTEMS by Elizabeth Christine Tehan December 1, 2006 A dissertation submitted to the Faculty of the Graduate School of The State University of New York at Buffalo in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Chemistry UMI Number: 3244233 Copyright 2007 by Tehan, Elizabeth Christine All rights reserved. UMI Microform 3244233 Copyright 2007 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code.

ProQuest Information and Learning Company 300 North Zeeb Road P. Box 1346 Ann Arbor, MI 48106-1346 In memory of my beloved mother, Mrs. Bertha (Kawam) Tehan (1946-2001) “The purpose of life is to live it, to taste experience to the utmost, to reach out eagerly and without fear for newer and richer experience.” Eleanor Roosevelt “Live as if you were to die tomorrow. Learn as if you were to live forever.” Mahatma Gandhi ii Acknowledgements I have been blessed by God with my talents and the ability to share them with people around me.

Named or otherwise, these people have invaluably helped me. Though words cannot express my thanks and appreciation to them, the impact they have had and continue to have on my life will never be overlooked. I would like to express my sincere appreciation to my advisor, Professor Frank V. Your leadership and wisdom have helped shape me both professionally and personally.

Moreover, I thank you for your patience and understanding, despite the times I felt undeserving. You are a great Teacher and Individual. I have been afforded the opportunity to work with many exceptional professionals. This includes my Ph.

committee: Professors Luís A. Detty and Troy D. This also includes Drs. Cartwright and Albert H.

Your insight and guidance as a group and individually, have helped me greatly and I have deep respect for each of you as professionals. In addition, special thanks to Dr. Brian MacCraith, for allowing me the memorable experience of working with the NCSR group at Dublin City University. I would like to acknowledge others too numerous to mention, including past and present Bright Group Members.

Much of this work may not have been done without the help of: Drs. Eun Jeong Cho, Ying Tang, Zunyu Tao, Michael Davenport, Vamsy Chodavarapu, and Ms. Rachel Bukowski, Mr. William Holthoff and the exceptionally skilled machinists in the UB Arts & Sciences Machine Shop.

Thank you all for your collaborations and friendships. Some people whose life’s path crosses our own forever impact us. For me, one such person is Mr. I can only thank you for the way iii compliment me immeasurably and for your love and companionship.

You and your family have been so welcoming and supportive of me; thank you. I look forward to our continued love and friendship. My entire extended family and friends have always supported me, especially through this endeavor, and I am so fortunate to be among them. I regret that some, who are dear to my heart, are not here to share in this accomplishment.

My immediate family has been outstanding. I am so proud of and proud to be a part of them. My parents have supported my education in every way and I am eternally grateful for that. They have always shown me love and encouragement.

Mom, you have taught me so much though your life and your memory. Dad, you have been my inspiration and motivation. Thank you to my sister, Victoria who, with her husband, Timothy and children, Andrew and Ryan have extended their family to include me. I appreciate our time together and the way you have opened your home to me.

Thank you to my brother, Louis and his wife Wendy, though we are not close in distance, I appreciate your confidence in me and motivation to excel in everything I do. Thank you to my brother, Joseph. I appreciate your heartening outlook on life and the way you share your humor with me, always making me smile. I love each of you dearly and thank you for your unending love and encouragement.

Finally, each project discussed in this document was made possible by financial support from various agencies and are gratefully acknowledged. These agencies include: the National Science Foundation, the Gerald A. Sterbutzel Fund at UB, the John R. Oishei Foundation, the Office of Naval Research, and the Interdisciplinary Research and Creative Activity Fund of the State University of New York at Buffalo.

iv Contents Dedication ii Acknowledgements iii List of Figures xi List of Tables xviii List of Acronyms and Symbols xix Abstract Chapter 1.1 Sensors and Sensor Arrays 1 1.2 Sensors and Instrument Design 5 1.3 Research Goals and Dissertation Scope 6 1.1 Sol-Gel Derived Sensor Materials that Yield Linear Calibration Plots, High Sensitivity, and Long Term Stability 6 1.2 Tailored Xerogel-Based Sensor Arrays and Artificial Neural Networks Yield Improved O2 Detection Accuracy and Precision 7 1.3 Creating a Diverse Sensor Response from a Single Sensor Element Using Phase Fluorimetry 7 1.4 Chemical Sensing Systems Using Xerogel-Based Sensor Elements and CMOS Photodetectors 8 v 1.5 Tailored Quartz-Based Pins for High-Density Microsensor Array Fabrication 9 1.1 Immobilization Through the Sol-Gel Process 15 2.3 Pin Printed Sensor Arrays 21 2. Sol-Gel Derived Sensor Materials That Yield Linear Calibration Plots, High Sensitivity and Long-Term Stability 31 3.2 Preparation of [Ru(dpp)3]2+- doped Octyl-triEOS/TEOS Composite Xerogel Sensing Films 35 3.4 Results and Discussion 38 3.2 Average Sensitivity and Stability 38 3.3 Stern-Volmer Plots 46 vi 3.4 Time-Resolved Intensity Decays 50 3. Tailored Xerogel-Based Sensor Arrays and Artificial Neural Networks Yield Improved O2 Detection Accuracy and Precision 64 4.2 Sol Stock Solution Preparation 70 4.3 Luminophore-doped Sol Solution Preparation 70 4.4 Sensor Array Fabrication 70 4.1 Instrumentation for Characterizing the Arrays 72 4.6 Results and Discussion 73 4.1 Tunable Response Profiles 73 4.2 Artificial Neural Networks to Improve Overall Sensor Performance 80 4.3 Performance of Sensor Elements After Contact with Rat Plasma or Whole Rat Blood 88 vii 4. Creating Diversified Response Profiles from a Single Quenchometric Sensor Elements by Using Phase-Resolved Fluorescence 99 5.2 Preparation of [Ru(dpp)3]2+- doped Xerogel Sensing Films 105 5.4 Results and Discussion 109 5.

Chemical Sensing Systems Using Xerogel-Based Sensor Elements and CMOS Photodetectors 117 6.1 Luminescence- Based Quenching: Recognition and Transduction 119 viii 6.1 Xerogel-Based Sensor Elements 122 6.3 Preparation of the Sol-Gel Processed Solution 123 6.4 CMOS Photodetector Array Detection System 125 6.5 System Configuration and Testing Protocols 135 6.6 Results and Discussion 141 6.2 Comparison of Xerogel-Based Sensor Systems Using CMOS, PMT, and CCD Detectors 141 6.3 Comparison of Other Analytical Figures of Merit 146 6.4 Detector Power Consumption 146 6. Tailored Quartz-Based Pins for High-Density Microsensor Array Fabrication 151 7.1 Chemical Reagents 152 ix 7.3 Preparation of Pin Silanization Solutions 153 7.4 Preparation of Luminophore-Doped Sol 153 7.5 Quartz Pin Fabrication 157 7.6 Quartz Pin Tip Silanization 157 7.3 Results and Discussion 162 7. Conclusions and Future Directions 173 8.3 References 176 x List of Figures Figure 1.1 A simplified schematic of a chemical sensor system. (B) An enlarged view of a sensor element.1 A description of the sol-gel process.

(A) The simplest sol-gel process for a tetraalkoxysilane. (B) The sol-gel process for a Class II ORMOSIL.2 A simplified Jablonski diagram describing luminescence spectroscopy 20 Figure 2.3 (A) Photograph of the Cartesian Technology model MicroSys 5100 array printing system, showing a microwell plate platform, a washing station, pins in the pin mount and substrate platforms. (B) Pins loaded in the pin mount for printing.4 (A) Photograph of a quill pin and (B) mechanism for printing with this type of pin. (C) Photograph of a 200 µm solid pin and (D) its printing mechanism.1 SEM images of Octyl-triEOS/TEOS composite xerogel films (TEOS sample aged for two months, all other samples aged for xi three months).2 SEM images of the varios regions of the 80% Octyl-triEOS/ 20% TEOS xerogel film showing phase separation and heterogeneity.3 Effects of aging time and xerogel composition on the O2 sensitivity 44 Figure 3.4 Typical Stern-Volmer plots for [Ru(dpp)3]2+-doped Octyl-triEOS/TEOS xerogels that have aged for three months.

The solid lines represent the best fit to a Demas model (TEOS) or Stern-Volmer model (all others).5 Effects of xerogel composition on the average Stern-Volmer quenching constant for three month old samples.6 Typical excited-state luminescence intensity decay traces for [Ru(dpp)3]2+-doped Octyl-triEOS/TEOS xerogel composites in an N2 environment. Xerogels have been aged for three months. (B) 20% Octyl-triEOS / 80% TEOS. (C) 40% Octyl-triEOS / 60% TEOS.(D) 50% Octyl-triEOS / 50% TEOS.

(E) 60% Octyl-triEOS / 40% TEOS.7 Effects of xerogel composition on the average [Ru(dpp)3]2+ excited-state fluorescence lifetime and the bimolecular quenching constant.1 Chemical structures of the precursors and lumiophores used in this research.2 O2-dependent false color images from an array of O2 responsive xerogel- based sensor elements based on co-doping [Ru(bpy)3]2+ and [Ru(dpp)3]2+ within C8-TEOS/TEOS xerogels.1 for the compositions of sensor elements labeled 1-5.3 Typical intensity-based Stern-Volmer plots for the sensor elements shown in Figure 4. The lines that pass through the data represent the best fit to Eq.4 Simplified schematic of a single pore within the C8-TEOS/TEOS class II xerogel showing the envisaged distribution of [Ru(bpy)3]2+ and [Ru(dpp)3]2+ molecules.5 Illustration of the (A) Forward and (B) Backward propagation for training the MLP.6 Typical intensity-based Stern-Volmer plots for O2 responsive sensors before and after being subjected to rat plasma and rat whole blood. The lines that pass through the data represent the best fit to Eq. The recovered parameters that describe the response profiles are compiled in Table 4.1 Traditional approaches that have been used to create a continuum of response profiles from a chemical sensor.

Three hypothetical sensor elements are shown under each approach which would yield three different response profiles to a particular target analyte.2 Frequency-domain luminescence schematics. (A) Phase- modulation concept. Excitation (ex), emission (em), and the luminescence phase shift (θ) are shown. The shaded region denotes the area under the modulated emission that is integrated by the π gate.3 Simplified phase-sensitive instrument schematic.

The xiv modulation frequency (f) is controlled by the function generator, the detector phase angle (θD) is adjusted by the lock-in amplifier, and the sample composition that reaches the sensor element is controlled by the mass flow controllers.4 Simulated (A, B) and experimental (C, D) O2-dependent, phase sensitive Stern-Volmer plots for the [Ru(dpp)3]2+-doped octyl- triEOS/TEOS-based xerogels at f = 20 kHz. In the simulations τ0 = 5.5 Simulated (A, B) and experimental (C, D) O2-dependent, phase sensitive Stern-Volmer plots for the [Ru(dpp)3]2+-doped octyl- triEOS/TEOS-based xerogels at f = 50 kHz. In the simulations τ0 = 5.1 The 40-pin DIP package for CMOS detectors.2 (A) Photograph of the photodetector array. The top three rows are phototransistors and bottom three rows are photogates.3 I-V relationship for the APS circuit.4 Photograph of a lateral p-n-p phototransistor.5 (A) Block diagram of the setup.

The sensor/detector system can be stand-alone, but the data analysis component is also shown to highlight the testing and evaluation of the sensor system. (B) Diagram of the LED light source, sensor element film, optical filters, sample flow chamber, and CMOS-based chip detector.6 Photograph of sensor sample chamber (flow cell holder with inlet and exhaust), mounting apparatus, optical filter, CMOS chip and circuit board.7 (A) Stern-Volmer plot and (B) Modified Stern-Vomer plot for each detector type.1 Digital photographs of the five pin types evaluated in this research. (The scale is different in each image; the tip dimension is noted in each panel.2 The quartz pin system. (A) Pin holder schematic.

(B) Pin holder photograph. (C) Quartz pin silanization/cleaning reservoir photograph.3 Cycling protocol for cleaning, silanizing, and stripping the quartz pins.4 False color fluorescence images of Rhodamine 6G-doped C8-TEOS/TEOS-based xerogels printed with 600, 400 and 200 µm diameter solid tungsten (A-C, respectively), 75 µm stainless steel quill (D), and 12 µm fused silica pins (virgin) (E).5 False color fluorescence images for Rhodamine 6G-doped pin printed xerogels. (A) Clean quartz pin and C8-TEOS/TEOS. (B) C8-silanized quartz pin and C8-TEOS/TEOS.