1. 논문관련 분야의 소개, 동향, 전망을 설명, 연구과정에서 생긴 에피소드 Infectious disease is one of the leading causes of global morbidity and mortality despite the fact that many of these diseases are treatable if addressed with proper therapy or medication at the early stage of infection. The prevalence of infectious disease is reported to be more significant in resource-poor settings where there is limited access to centralized laboratory and clinical facilities. For example, in the low-income countries, infectious diseases account for 68% of years of life lost compared to only 8% in high-income countries. However, current disease diagnostic approaches are either unavailable/unaffordable in many developing countries (i.e. PCR or ELISA), or have very low analytical sensitivity and provide only qualitative data (i.e. Lateral flow test). Consequently, there is an increasing demand for cost-effective and portable point-of-care diagnostic system for effective on-site monitoring of infectious viral loads and early detection of diseases. Our study aimed to address this issue by combining recent advances in quantum dot (QD) barcode technology with smartphones and isothermal nucleic acid amplification technique to engineer a simple and low-cost multiplex diagnostic device. QDs are advantageous over organic fluorophores for generating optical barcodes because they have better photo-stability, size-tunable emission wavelength, narrower fluorescence spectra, and wider excitation spectra permitting excitation of multiple colors with a single-wavelength laser source. In a typical QD barcode assay, recognition molecules are conjugated to the surface of QD-encoded microbeads, and target biomarkers bind to these recognition molecules and fluorescently labeled detection probes. There are two optical signals generated from this complex: the first signal is emitted from QDs embedded inside microbeads, which distinguishes the identity of biomarker present in the samples, and the second signal is generated from detection probes, which identifies the presence or absence of a biomarker. QD barcode assay is advantageous over other methods as it allows simultaneous detection of multiple infectious biomarkers in a single multiplexed reaction. A smartphone camera accompanied with proper optics and lenses was used to capture fluorescent signals generated from QD barcodes, and enabled diagnosis of patients infected with human immunodeficiency virus and/or hepatitis B virus. In the near future, we envision integrating all components that are required for diagnosis from sample collection to running molecular assay into a single device unit for field-testing and point-of-care applications. 2. 연구를 진행했던 소속기관 또는 연구소에 대해 소개 부탁 드립니다. I work at the Integrated Nanotechnology & Biomedical Sciences Laboratory (INBS) under the supervision of Dr. Warren Chan as part of Institute of Biomaterials and Biomedical Engineering (IBBME) program in University of Toronto. Our lab specializes in studying nanomaterial interactions with biological systems and bio-molecule sensing. More information can be found in this website: http://inbs.med.utoronto.ca/ 3. 연구활동 하시면서 평소 느끼신 점 또는 자부심, 보람 I am always very motivated to work in this field because it has a great potential to directly improve our quality of lives. Personally, I was very excited to improve our limit of detection by 6 orders of magnitude by integrating isothermal nucleic acid amplification technique with QD barcode assay as it led us to take a step forward in this study and allowed us to test real patient samples. 4. 이 분야로 진학하려는 후배들 또는 유학준비생들에게 도움이 되는 말씀을 해 주신다면? After spending three years of time in graduate school, I found that one of the most important aspects of doing research is consistency. I still remember my first year of PhD when I was endlessly failing experiments, but I believe those consistent failures finally led me to great findings at the end. 5. 연구활동과 관련된 앞으로의 계획이 있으시다면? My current study explores how multiplexed detection can be used to improve diagnostic sensitivity. In the near future, I am interested in investigating various genotypes of hepatitis B virus patients, and correlating that information with disease progression and treatment methods. 6. 다른 하시고 싶은 이야기들.... I would like to first thank my advisor, Dr. Warren Chan, for his support and guidance throughout this study. I also want to acknowledge the co-first author of this paper, Kevin Ming, and our clinical collaborators especially Dr. Mia Biondi and Dr. Jordan Feld.