Applications Of Laser-Induced Breakdown Spectroscopy (Libs) In Biomedical

Principle of Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) has enormous potential in biomedicine. This technique uses a laser pulse to create a tiny plasma cloud in a sample, revealing its elemental makeup through a unique light signature. LIBS holds promise for cancer diagnosis by differentiating healthy from cancerous tissues, monitoring treatment response by tracking changes in elemental composition, and even studying drug delivery by tracing drug elements within tissues. Its non-invasive nature and rapid analysis capabilities make LIBS a valuable tool for the future of medical diagnostics and treatment.

The main process of LIBS:

1. Laser Pulse: A high-powered, short-pulsed laser beam is focused onto the sample surface.

2. Breakdown: The intense energy from the laser pulse causes the material to rapidly heat up and ionize, creating a tiny, hot, and highly localized region of ionized gas called a plasma plume.

3. Excitation: The elevated temperature within the plasma excites the electrons in the atoms of the sample material. As these excited electrons return to their ground states, they emit light at specific wavelengths.

4. Emission Analysis: This emitted light, characteristic of the elements present in the sample, is collected by a spectrometer, and analyzed.

Figure 1 shows schematic of the principle behind Laser-Induced Breakdown Spectroscopy (LIBS). A pulsed laser beam is first focused onto the surface of the material being analyzed (1). This intense radiation energy is then locally coupled into the material (2), causing it to evaporate (3). The vaporized material and surrounding gas atmosphere combine to form plasma (4). This plasma excites the elements within the sample, leading them to emit characteristic radiation (5-7). This emitted light fingerprint is then spectrally resolved and detected by a spectrometer. Notably, for solid samples, a crater is formed at the point of interaction (8).

Figure 1: Laser-Induced Breakdown Spectroscopy working process diagram. LB: Laser-beam. S: sample. H: region of energy deposition. V: material vapor. P: plasma. E: element-specific emission. CR: crater. PT: particles.

Applications of LIBS in biomedical

Laser-induced breakdown spectroscopy (LIBS) offers several exciting applications in the field of biomedicine, thanks to its unique capabilities:

• Non-invasive Tissue and Biofluid Analysis: Unlike traditional biopsy procedures, LIBS allows for analysis of tissues and biofluids without causing any harm. This is particularly beneficial for sensitive areas or when repeated measurements are needed.
   
• Rapid Diagnosis: LIBS delivers fast analysis times, enabling quicker diagnoses and allowing for timely treatment decisions. This can be crucial in situations where early intervention is critical.
• Detailed Elemental Detection: LIBS excels at detecting a wide range of elements, including lighter elements like carbon, hydrogen, nitrogen, and oxygen, which are essential components of biomolecules. This comprehensive analysis provides valuable insights into the elemental makeup of biological samples.

Here is how these capabilities translate into specific biomedical applications:

• Cancer Diagnosis: LIBS holds promise for differentiating between cancerous and healthy tissues based on subtle variations in their elemental composition. This could potentially aid in early cancer detection and improve diagnostic accuracy.
• Monitoring Treatment Response: By tracking changes in the elemental makeup of tissues after treatment, LIBS can help monitor the effectiveness of cancer therapies, allowing for adjustments if needed.
• Drug Delivery Studies: LIBS can be used to track the distribution and localization of drug elements within tissues. This information is valuable for optimizing drug delivery strategies and ensuring targeted treatment.
• Dental Applications: Analyzing the elemental composition of teeth can be crucial in dentistry. LIBS can identify deficiencies in essential minerals like calcium and assess the effectiveness of dental treatments.
• Understanding Physiological Processes: By analyzing the elemental composition of various biofluids like blood or saliva, LIBS may contribute to a deeper understanding of physiological processes and potential disease markers.

RESULT

Figure 2: Gallstone sample with surface view (Left) and cross-section view (Right).

In a specific application Laser-induced breakdown spectroscopy (LIBS) is used to analyze gallstones that obtained from different patients from India. Figure 2 shows the surface and cross-sectional of a gallstone sample. The LIBS aimed to identify all the minerals present in the sample.

Figure 3: LIBS spectral of gallstone sample at the wavelength in range of 320nm to 332nm shows presence of elements copper and sodium.

Figure 4: LIBS spectral of gallstone sample at the wavelength in range of 570nm to 780nm shows presence of elements sodium, calcium, hydrogen, nitrogen, potassium, and oxygen.

The LIBS technique captured light signatures (spectra) of the gallstones in various wavelength ranges. In figure 4 shows atomic lines for sodium (589.5nm), and potassium (766.4nm and 769.8nm). Notably, LIBS even detected lighter elements like hydrogen (656.2nm), nitrogen (744.2nm), and oxygen(777.1nm), highlighting its advantage over traditional methods.

MEASUREMENT SYSTEM

Figure 5: Ocean HR2000+ spectrometer.

Figure 6: Ocean Insight 532nm laser light source.

The Ocean HR2000+ spectrometer paired with the Ocean Insight 532nm laser light source forms a powerful combination for LIBS applications in biomedicine. The HR2000+ spectrometer boasts a high-resolution spectral range, crucial for accurately capturing the distinct light signatures (emission lines) of various elements present in biological samples. This detailed analysis allows for the identification of a wider range of elements, including lighter elements like those found in biomolecules. Additionally, the Ocean Insight 532nm laser light source provides a focused and stable laser pulse, ideal for creating the plasma cloud within the sample needed for LIBS analysis. This precise laser source ensures consistent results and minimizes potential damage to delicate biological samples. Together, the Ocean HR2000+ spectrometer and Ocean Insight 532nm laser light source provide a robust and reliable LIBS system for the non-invasive and rapid analysis of tissues and biofluids in biomedical research and potentially future clinical applications.

CONCLUSION

Laser-Induced Breakdown Spectroscopy (LIBS) is a powerful analytical technique with significant potential in biomedical applications. It utilizes a focused laser pulse to generate a plasma cloud from a sample, allowing for the detection of elemental composition through emitted light signatures. LIBS is particularly promising for cancer diagnosis, treatment monitoring, and drug delivery studies due to its non-invasive nature and rapid analysis capabilities. For instance, in a study analyzing gallstones from patients in India, LIBS identified various minerals and elements, including lighter ones like hydrogen and oxygen, which are often challenging to detect with traditional methods. The Ocean LIBS 2000+ system exemplifies the technique’s advantages, offering high-resolution spectral analysis and the ability to analyze delicate tissues and biofluids without causing harm, thereby holding great promise for advancing medical diagnostics and treatment.