A new DNA chip detection mechanism using optical pick-up actuators

Today, most of the DNA-chip detection mechanisms use fluorescent dyes. The fluorescence based detection methods achieve remarkable performance in terms of sensitivity and accuracy as compared to other detection technologies. However, the conventional mechanisms to detect the fluorescent level require the high positioning accuracy and manufacturing cost, especially when diagnostic chips are used. In this paper, we propose a new optical detection method for DNA-chip using optical pick-up technology which is widely used in optical storage devices. The new detection mechanism uses a commercial DVD pick-up with 650 nm laser diode by modifying optical path. The 650 nm laser beam is used for the dynamic autofocusing and exciting fluorescence light of Cy5 dye. The fluorescence light emitted from Cy5 dye, is measured by a detector with high sensitivity. The real-time focusing control by a voice coil motor actuator enables high scan speed, low optical distortion and high alignment robustness, which are superior to conventional DNA-chip scanners with the expensive and bulky mechanisms. Finally, this paper shows the experimental results and verifies the feasibility of the new DNA-chip detection mechanism to meet both high performance and low cost.