Development of a Portable SPR Sensor for Nucleic Acid Detection

Area of Science:

• Biosensing
• Analytical Chemistry
• Optical Physics

Background:

• Nucleic acid detection is crucial for diagnostics, environmental monitoring, and food safety.
• Surface Plasmon Resonance (SPR) offers label-free, real-time detection advantages over traditional methods.
• Existing SPR angle modulation systems often require complex mechanics and high-resolution motors.

Purpose of the Study:

• To design and develop a portable multi-angle scanning SPR sensor.
• To simplify the mechanical structure of SPR angle scanning.
• To demonstrate the sensor's capability for nucleic acid hybridization detection.

Main Methods:

• A novel mechanism using a single stepping motor to rotate a belt, driving opposing movement of incident and reflected light linkages.
• Achieved SPR angle scanning by maintaining equal incident and reflected angles.
• Utilized a gold film chip modified with bovine serum albumin (BSA) for detection.

Main Results:

• The sensor achieved an angle scanning accuracy of 0.002° and a response sensitivity of 3.72 × 10^-6 RIU.
• The system exhibits a compact size (480 mm × 150 mm × 180 mm) and a wide scanning range (30°-74°).
• Successfully detected nucleic acid hybridization of target DNA solution at 0.01 μmol/mL with high sensitivity and fast response.

Conclusions:

• The developed portable SPR sensor simplifies SPR systems with an innovative mechanical design.
• The sensor demonstrates high performance, including sensitivity, accuracy, and a compact form factor.
• This technology is suitable for sensitive and rapid nucleic acid detection in various applications.