Stabilization method for signal drifts in terahertz chemical microscopy

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Biophysics

Background:

• Terahertz chemical microscopy (TCM) is susceptible to signal drifts caused by environmental variations like temperature and pH.
• These drifts can obscure subtle chemical signals, limiting the sensitivity and reliability of TCM analyses.
• Accurate detection of chemical reactions and molecular interactions requires robust methods to mitigate these signal fluctuations.

Purpose of the Study:

• To develop and validate a stabilization method for terahertz chemical microscopy (TCM) to counteract signal drifts.
• To improve the precision and reliability of TCM by compensating for environmental changes.
• To demonstrate the enhanced detection capabilities of TCM after stabilization.

Main Methods:

• A dual-area sensing plate was designed, comprising a detection area and a control area.
• Terahertz (THz) pulses from both areas were interfered, with the control area compensating for environmental changes.
• Signal stabilization was achieved by precisely timing the interference of THz pulses from the detection and control areas.

Main Results:

• The method effectively stabilized signal deviations from 390 to 31 under environmental changes (38 °C temperature, pH 8.33).
• The stabilized TCM system achieved a signal shift detection of 121 for immobilized 275-nmol/L immunoglobulin G.
• This demonstrates a significant improvement in the signal-to-noise ratio and detection limit.

Conclusions:

• The proposed stabilization method significantly enhances the robustness of terahertz chemical microscopy.
• This technique allows for more accurate and sensitive detection of chemical reactions and biomolecular interactions.
• The developed method paves the way for more reliable quantitative analysis using TCM.