Polypropylene CD-organic light-emitting diode biosensing platform

This paper describes the development of a compact platform for simultaneous photoluminescence (PL)-based sensing of multiple bioanalytes using a lab-on-CD. The platform is based on microfluidic features generated on foamed polypropylene (PP) surfaces by ultrasonic micro-embossing, sub-micron thick organic light-emitting diode (OLED) pixels that serve as the PL excitation sources, and a compatible array of compact photodetectors (PDs). The localized heating resulting from the ultrasonic micro-embossing enables generation of flash-free micro-patterns on the foamed PP surfaces. The embossed features are designed to function as reservoirs, channels, valves, and reaction chambers, to allow, in combination with compact OLED/PD arrays, the simultaneous monitoring of glucose, lactate, ethanol, and dissolved oxygen (DO) in four separate single CD segments using a standard PC-CD player. The analytes' concentrations are determined following CD rotation for reagent mixing by measuring the DO level via the PL decay time of an oxygen-sensitive dye following an OLED excitation pulse. Glucose, lactate, and ethanol are monitored following their oxidation in sealed cells in the presence of oxygen and their specific oxidase enzyme, which results in consumption of DO. Calibration curves for each of the analytes and their concentrations in mixtures were monitored on the four separate segments of the bio-CD. The attributes and utility of the compact OLED-bio-CD-PD platform for sensitive and accurate monitoring of multiple analytes, and its potential field-deployability, are discussed.