Microoptical Fluorescence Detection for Chip-Based Multiplexed Analysis Systems

Abstract

A diffractive optical element (DOE) made of fused silica, known as Dammann grating [1], multiplex a laser beam into a beam matrix of identical beam profile. This robust optical configuration is used to simplify the architecture of fluorescence chip-based multiplexed systems. The emission detection system can be either a large one-to-one imaging system made of two conventional micro-objectives or, a more compact detection unit, made with a stack of microlens arrays (μLAs) [2]. As photo-detector, both emission detection systems feature either a miniaturized multi-anodic PMT or sensitivity enhanced CCD camera. The combination of the Dammann grating based excitation, and the μLAs based emission detection resulted in two true μTAS multiplexed miniaturized fluorescence systems intended for medical diagnostic and chemical analytical purposes. One device is a Multichannel Fluorescence Planar Waveguide Bioaffinity Sensor, and the other a Multilane Chip-based Capillary Electrophoresis System The Dammann based excitation system has also been demonstrated in applications for hight throughput screening purposes.