pH- and nitroreductase-responsive SERS acupuncture needles enabling ratiometric detection in both solution and tissue...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Tissue pH and nitroreductase (NTR) detection are vital for diagnosing tumor hypoxia and understanding acid-base balance.
• Current detection methods often require destructive sample pretreatment, compromising tissue integrity.
• Acupuncture needles offer a minimally invasive alternative for in-tissue analysis.

Purpose of the Study:

• To develop a novel probe for simultaneous, non-destructive detection of pH and NTR in intact tissues.
• To utilize surface-enhanced Raman spectroscopy (SERS) for sensitive and accurate measurements.
• To overcome the limitations of traditional destructive sample analysis methods.

Main Methods:

• Development of a probe comprising acupuncture needles, gold nanoparticles (Au NPs), and 5-mercapto-2-nitrobenzoic acid (MNBA).
• Application of the ANs@Au NPs@MNBA probe for SERS-based detection in solution and intact tissue samples.
• Validation of the probe's performance across specified pH and NTR concentration ranges.

Main Results:

• The developed probe enabled simultaneous ratiometric detection of pH and NTR.
• Excellent linear responses were observed for pH (4.75–7.25) and NTR (0–20.0 μg/mL).
• The method proved effective for analyzing both solution and intact tissue samples.

Conclusions:

• The novel acupuncture needle-based SERS probe offers a non-destructive approach for in-situ tissue analysis.
• This technology provides valuable insights into tissue microenvironments, crucial for disease diagnosis and physiological studies.
• The method advances the field of biosensing for complex biological samples.