Nonmagnetic Biomarker Detection by Nanocatalytic-Amplified Quantum Spin Relaxometry

Area of Science:

• Quantum Sensing
• Nanotechnology
• Biomarker Detection

Background:

• Nitrogen-vacancy (NV) centers in diamond offer excellent photostability and spin coherence for biosensing.
• Clinical NV center applications are hindered by poor responsiveness to nonmagnetic biomolecules.
• Tyrosinase (TYR) is a critical biomarker for melanoma detection.

Purpose of the Study:

• To develop a nanocatalytic-amplified quantum sensing platform for ultrasensitive tyrosinase detection.
• To overcome the limitations of NV centers in sensing nonmagnetic biomarkers.
• To enable minimally invasive melanoma screening.

Main Methods:

• Fabrication of plasmonic nanodiamond (FND@Au-Ag) functionalized hydrogel microneedles.
• Utilizing nanocatalytic signal transduction for hydroxyl radical generation triggered by TYR.
• Implementing an AND logic gate based on spin relaxation time (T1) dynamics.
• Integrating fluorescence, colorimetry, and T1 signals for detection.
• Employing a genetic algorithm-optimized backpropagation neural network for data analysis.

Main Results:

• Achieved ultrasensitive detection of tyrosinase (TYR).
• Established a wide dynamic detection range of 0.01-200 U/mL for TYR.
• Reached an ultralow detection limit of 0.003 U/mL for TYR.
• Demonstrated enhanced reliability in complex biological matrices using a neural network.

Conclusions:

• The nanocatalytic-amplified quantum sensing platform effectively detects nonmagnetic biomarkers like TYR.
• This approach overcomes inherent limitations of traditional quantum sensing for nonmagnetic targets.
• The platform shows promise for minimally invasive melanoma screening.