Dual-Mode Undistorted Visual Fluorescent Sensing Strategy through Manipulating the Coffee-Ring Effect on Microfluidic...

Area of Science:

• Analytical Chemistry
• Biomedical Engineering
• Nanotechnology

Background:

• Smartphone-based fluorescent sensing offers convenience but suffers from image distortion.
• Microfluidic paper-based analytical devices (μPADs) require sensitive and accurate detection methods.
• Existing methods struggle with quantitative analysis due to optical artifacts.

Purpose of the Study:

• To develop a novel dual-mode strategy for undistorted visual fluorescent sensing on μPADs.
• To enhance the sensitivity and accuracy of smartphone-based fluorescent detection.
• To enable rapid and convenient analysis of histidine in human urine.

Main Methods:

• Manipulating the coffee-ring effect to control fluid sample behavior on μPADs.
• Developing a dual-mode analysis strategy involving RGB pixel analysis and fluorescent strip length measurement.
• Utilizing bovine serum albumin-stabilized gold nanoclusters-copper ion complex as a fluorescent probe.
• Employing a smartphone and a small imaging box for data acquisition.

Main Results:

• Achieved improved anti-distortion for visual fluorescent sensing.
• Quantitative analysis of fluorescence images by dividing the horizontal direction into 600 pixels.
• Established a limit of detection (LOD) of 0.021 mM for RGB analysis and 0.5 mM for strip length measurement.
• Demonstrated rapid and convenient testing of histidine in human urine.

Conclusions:

• The novel dual-mode strategy effectively overcomes smartphone-induced fluorescent image distortion on μPADs.
• This approach significantly enhances quantitative accuracy and sensitivity for visual fluorescent sensing.
• The developed method shows great potential for point-of-care diagnostics and field applications.