Optofluidic ultrahigh-throughput detection of fluorescent drops

Area of Science:

• Optofluidics and Microfluidics
• Biosensing and Diagnostics
• High-Throughput Screening

Background:

• Conventional droplet interrogation methods face limitations in throughput due to trade-offs between light collection efficiency and field of view.
• There is a need for advanced devices capable of rapid and efficient analysis of fluorescent droplets for various scientific applications.

Purpose of the Study:

• To develop and characterize an optofluidic droplet interrogation device with unprecedented throughput.
• To demonstrate a novel microfluidic-sensor integration for enhanced fluorescence signal collection.

Main Methods:

• Fabrication of a device integrating 16 parallel microfluidic channels directly bonded to a filter-coated Complementary Metal-Oxide-Semiconductor (CMOS) sensor array.
• Utilizing the sensor array as the bottom of the microfluidic channels for direct fluorescence signal collection from droplets.
• Measuring the droplet interrogation rate, limited by the CMOS sensor's acquisition speed.

Main Results:

• Achieved a record droplet interrogation throughput of 254,000 drops per second.
• Demonstrated efficient fluorescence collection due to the close proximity of droplets to the sensor.
• Identified CMOS sensor acquisition speed as the primary limitation for further rate increases.

Conclusions:

• The developed optofluidic device offers the highest published droplet interrogation rate to date.
• The integrated microfluidic-sensor design overcomes conventional microscopy limitations for efficient fluorescence detection.
• Future advancements in sensor technology are expected to further enhance the device's already high throughput.