Cam-based vibration-counter-balanced laser-induced fluorescence scanner for multiplexed capillary detection

Area of Science:

• Analytical Chemistry
• Instrumentation
• Biophysical Chemistry

Background:

• Multiplexed capillary detection using laser-induced fluorescence (LIF) is crucial for various analytical applications.
• Existing LIF rotary scanners require circular capillary formats, and linear scanners suffer from motor-induced noise and vibration, limiting capillary capacity.
• These limitations hinder efficient and sensitive multiplexed capillary analysis.

Purpose of the Study:

• To develop an improved cam-based LIF scanner that overcomes the limitations of existing rotary and linear systems.
• To enhance the sensitivity and capillary capacity for multiplexed LIF detection.
• To demonstrate the instrument's utility in capillary electrophoresis and chip-capillary hybrid devices.

Main Methods:

• Construction of a cam-based scanner designed to eliminate motor acceleration/deceleration noise.
• Incorporation of a counter-balanced dual scanning head mechanism to mitigate mechanical vibrations.
• Testing the modified scanner's performance in terms of limit of detection and capillary number capacity.

Main Results:

• The counter-balanced cam-based scanner improved the limit of detection for fluorescein by over 3 times (from 69 pM to 20 pM).
• Capillary number capacity was increased by over 6 times, accommodating up to 426 capillaries (150-μm o.d.) or 320 capillaries (200-μm o.d.).
• Successful simultaneous monitoring of 99 capillaries during capillary electrophoresis and detection of fluorescently labeled proteins in a 2D chip-capillary hybrid device were achieved.

Conclusions:

• The developed counter-balanced cam-based LIF scanner effectively reduces instrumental noise and enhances detection sensitivity.
• The instrument significantly increases the number of capillaries that can be scanned, enabling high-throughput multiplexed analysis.
• This advanced scanner is suitable for demanding applications like capillary electrophoresis and complex hybrid separation devices.