Non-contact bacterial identification and decontamination based on laser-induced breakdown spectroscopy

Area of Science:

• Biotechnology
• Spectroscopy
• Public Health

Background:

• Bacterial agents pose significant threats as biological weapons.
• Current identification methods are slow, manual, and risk secondary contamination.
• Decontamination processes can involve hazardous materials or conditions.

Purpose of the Study:

• To develop a non-contact, non-destructive, and environmentally friendly technology for bacterial identification and decontamination.
• To utilize laser-induced breakdown spectroscopy (LIBS) for this dual purpose.
• To assess the efficacy and parameters of the proposed method.

Main Methods:

• Laser-Induced Breakdown Spectroscopy (LIBS) for bacterial identification.
• Principal Component Analysis (PCA) and Support Vector Machine (SVM) for classification model.
• Laser-induced low-temperature plasma with a vibration mirror for decontamination.
• Optimization of laser parameters (defocusing, repetition rate, scanning speed, number of scans).

Main Results:

• Achieved an average bacterial identification rate of 98.93% for seven common types.
• Demonstrated high performance metrics: true positive rate (0.9714), precision (0.9718), recall (0.9714), and F1-score (0.9716).
• Achieved a decontamination speed of 25.6 mm²/min with inactivation rates exceeding 98% for E. coli and B. subtilis, primarily through plasma effect.

Conclusions:

• The proposed LIBS-based technology offers a rapid, in-situ, non-contact solution for bacterial identification and decontamination.
• It eliminates the need for sample pretreatment and is suitable for sensitive materials.
• Potential applications span modern military, medical, and public health fields.