18^th World Analytical Chemistry & Mass Spectrometry August 29-30, 2018 Toronto, Ontario, Canada

Maria Ramos Payan has expertise in improving sample preparation techniques focused on microfluidic-chip devices as miniaturization. The novelty of her microfluidic devices offers more advantages than the existing methodologies. Maria has worked at different institutions (the University of Seville, University of Huelva, University of Lund, University of Copenhagen, University of North Carolina, USA, Microelectronic National Center of Barcelona and University of Autonoma Barcelona). Currently, she works at the University of Seville with the aim of implementing optical detection into microfluidic devices for multiple different applications

LEGO® building blocks have been patterned with laser so as to obtain photonic elements which can easily be combined into a photonic lab on a chip (PhLoC). As opposite to the monolithic integration, the building block architecture enable to modify only specific regions of the PhLoC. In addition, it allows to replace damaged parts without a complete breakdown of the system. In this context, different laser writing speeds and conditions have been tested so as to achieve light guides of 500 um in width and 500 um in depth on transparent LEGO® building blocks. Once the optimal writing conditions were achieved, they were used to implement absorbance-based filters using transparent but colored building blocks. Here, it has been obtained stopbands higher than 30 dB for blue transparent building blocks, which is the maximum dynamic range of the Maya Spectrometer (Ocean Optics) used. Finally, an experimental set-up was implemented by using a building block as a cuvette, and measurements in absorbance and fluorescence were pursued by placing lightguides either at 180° or at 90° from the input light guide. Measurements in absorbance showed a limit of Detection (LoD) of 0’0171 ppm using XXXXX as target analyte. When measuring fluorescence, two different compounds were tested: Fluorescein (LoD of 5.22 ppm) and Norfloxacine (22.82 ppm). The results presented herein allows confirming the possibility of defining PhLoC building blocks for absorbance and fluorescence measurements.

Maria Ramos Payan has expertise in improving sample preparation techniques focused on microfluidic-chip devices as miniaturization. The novelty of her microfluidic devices offers more advantages than the existing methodologies. Maria has worked at different institutions (the University of Seville, University of Huelva, University of Lund, University of Copenhagen, University of North Carolina, USA, Microelectronic National Center of Barcelona and Universitat Autónoma de Barcelona). Currently, she works at the University of Seville with the aim of implementing optical detection into microfluidic devices for multiple different applications

This work consists of the development and calibration of a microfluidic device for direct fluorescence detection. First, the microchip was evaluated and tested using fluorescein, a substance of high fluorescence, soluble in methanol, and widely used as a marker in methods of measuring other non-fluorescent substances. This microfluidic device was applied to the determination of an antibiotic commonly used for people and animals: norfloxacin. The measurements were carried out using two optical fibers, spectrometers and optical potentiometers at a wavelength of 278 y 445 nm. Finally, the microfluidic device was calibrated for norfloxacin with detection limits and quantitation limits of 0.07 mg/L and 0.24 mg/L, respectively. This device was satisfactorily applied in environmental samples, specifically to waters from the Llobregat River passing through Manresa, Barcelona. This has been demonstrated to be a low-cost device offering the short time of analysis and low detection and quantification limits. Additionally, this device is reusable and easy sampling to use.