SMARTPHONE BASED PAPER-PLASTIC MICROFLUIDIC CHEMILUMINESCENCE SENSOR SYSTEM FOR H202 DETECTION Elise Lebiga 1 , Katherine M Krenek 1 , Renny Edwin Fernandez 1 , Alexander Lippert 2 , Ali Beskok 1 1 Biomicrofluidics Laboratory, Department of Mechanical Engineering, 2 Department of Chemistry, 1, 2 Southern Methodist University ABSTRACT We report a disposable chemiluminescence sensor system for detection and quantification of micromolar levels of hydrogen peroxide (H202) using a hybrid paper/plastic disposable device incorporated to a smart phone (iPhone). A confined photon generation is achieved using a hybrid microfluidic device that consists of a) paper reaction pad and b) plastic microfluidic channels. The reagents are delivered to the reaction pad through plastic microfluidic channels, while the chemiluminescence, due to the reaction of Bis (2,4,6- trichlorophenyl) oxalate with H202 in presence of rubrene and Imidazole, is restricted to a hydrophobically isolated paper reaction pad. KEYWORDS: Paper microfluidics, chemiluminescence, smartphone, sensor system INTRODUCTION Chemiluminescence (CL) assays are up to five times more sensitive than absorption spectroscopy and 1000 times more sensitive than flurometry (Salama et al, 2004). Due to its sensitivity and easy instrumental setup, CL provides an attractive basis for rapid and inexpensive micro total analysis systems (µ-TAS) [Lv et al, 2003; Tsukagoshi et al., 2005]. Attempts have been made to integrate chemiluminescent sensing onto micro paper-pads [Yu, 2011]. We propose a novel way to incorporate chemiluminescence detection to a smartphone using a custom microfluidic device, and the results obtained were verified using an inverted research microscope configured with a CMOS digital camera. THEORY A paper-plastic hybrid microfluidic device (3 x 2 cm) with paper reactor pad (radius: 3 mm; A: 28 mm 2 ) and plastic microchannels (width: 1 mm, height: 250 μm) was fabricated using a precision craft cutter. Two laminating plastic films are bonded together surrounding an accurately aligned microfilter paper and cutout of the channel design; the two plastic films serve as mechanical backing and also enclose the microchannels. A custom built enclosure, that houses the smartphone and microfluidic device, enables video capture of chemiluminescent reaction without the interference of stray light (Fig. 2). Photon intensity of a CL reaction is captured using the inbuilt smartphone camera. Chemiluminescent intensity, I (t), at a given time is dependent on the concentration of the H202. Net photon emission, Np (t), of a CL reaction is quantified by integrating the decaying chemiluminescence intensities, over a period of time (Equations 1-2).    ) 2 ( ] [ ] [ ) 1 ( ] ][ [ ) ( ) ( ) ( ) ( 0 ] [ 0      T f p t E k f dt S k E VA t N e S E k VA dt t P d VA t I f    where α, V and A are quantum yield, volume of the reaction medium and Avogadro’s number respectively. RESULTS AND DISCUSSION The photon emission analysis of the reaction is quantified by integrating the intensity profile extracted through image processing of the Full HD 1080p videos recorded at 30 fps with 8 megapixel inbuilt iPhone TM 4s camera. The recorded HD videos were analyzed using a video processing software (VLC) to obtain the 100 µM 50 µM 10 µM 1 µM Fig 1: Video captures of peak chemiluminescent intensities for varying H202 concentrations 978-0-9798064-7-6/µTAS 2014/$20©14CBMS-0001 2568 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences October 26-30, 2014, San Antonio, Texas, USA