A microfluidic channel and light refraction simulation for micro-organism identification

A photonic bio-recognition system has the potential to be used with the advancement in a biosensor development. The system requires an optical sensing system, microfluidic device and biological reagent for microorganism detection. Although, biosensors are available in the market, a label free and a lab-on-chip approach will be a flexible solution. The main objective of this work is to develop photonic biosensor to identify immobilized analytes in a microfluidic channel by converted and digitized the reflection units from a voltages to digital values before send it to a computer for a refractive index computational analysis. The system developed involves a PIC24HJ32GP302 microcontroller as a core processing element for the instrumentation and communication application. A laser diode transmits a 650 nm light ray to the analyte inside the microfluidic channel that is placed upper to the metal-dielectric interface and a prism. The reflected light from the analyte will be converted and digitized respectively from CCD sensor and 16-bit ADC. Then, the digitized values will be send to the computer via a USB to UART converter. A Graphical User Interface (GUI) will be developed with a Microsoft Visual Basic 2017 that display and plot respectively graphs and measurement data. As a result the values of response unit (RU), refractive index (RI) and sample concentration for molecular interaction will be calculated quantitatively. This prototype is beneficial with flexibility as a label-free Point-Of-Care (POC) system that eliminates laborious work that was conducted manually. The POC system is expected to achieve instant measurement automatically with accurate result via Automatic Repeatability Sequences (ARS).