title: A novel CMOS image sensor system for quantitative loop-mediated isothermal amplification assays to detect food-borne pathogens.
abstract: Loop-mediated isothermal amplification (LAMP) is considered as one of the alternatives to the conventional PCR and it is an inexpensive portable diagnostic system with minimal power consumption. The present work describes the application of LAMP in real-time photon detection and quantitative analysis of nucleic acids integrated with a disposable complementary-metal-oxide semiconductor (CMOS) image sensor. This novel system works as an amplification-coupled detection platform, relying on a CMOS image sensor, with the aid of a computerized circuitry controller for the temperature and light sources. The CMOS image sensor captures the light which is passing through the sensor surface and converts into digital units using an analog-to-digital converter (ADC). This new system monitors the real-time photon variation, caused by the color changes during amplification. Escherichia coli O157 was used as a proof-of-concept target for quantitative analysis, and compared with the results for Staphylococcus aureus and Salmonella enterica to confirm the efficiency of the system. The system detected various DNA concentrations of E. coli O157 in a short time (45min), with a detection limit of 10fg/μL. The low-cost, simple, and compact design, with low power consumption, represents a significant advance in the development of a portable, sensitive, user-friendly, real-time, and quantitative analytic tools for point-of-care diagnosis.
authors.affiliation: Department of Bionanotechnology, Gachon University, San 65, Bokjeong-Dong, Sujeong-Gu, Seongnam-Si, Gyeonggi-Do 461-701, Republic of Korea.
authors.forename: Tiantian
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Bionanotechnology, Gachon University, San 65, Bokjeong-Dong, Sujeong-Gu, Seongnam-Si, Gyeonggi-Do 461-701, Republic of Korea; Graduate Gachon Medical Research Institute, Gil Medical Center, Inchon, 405-760, Republic of Korea. Electronic address: samkim@gachon.ac.kr.
authors.forename: Sanghyo
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Polymer Science & Engineering, Sungkyunkwan University, Suwon, Gyeonggi-Do 440-146, Republic of Korea. Electronic address: jhahn1us@skku.edu.
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: An
mesh_terms: D003362:Cost-Benefit Analysis; D004269:DNA, Bacterial / Q000302:isolation & purification*; D004867:Equipment Design; D019453:Escherichia coli O157 / Q000302:isolation & purification; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D057230:Limit of Detection; D021141:Nucleic Acid Amplification Techniques; D019779:Salmonella enterica / Q000302:isolation & purification; D012666:Semiconductors; D012680:Sensitivity and Specificity; D013211:Staphylococcus aureus / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial
keywords: CMOS-based LAMP system; Molecular diagnosis; Photon count variation; Quantitative analysis