Utilizing Laser-Induced Breakdown Spectroscopy (LIBS) of the nail for the detection of osteoporosis

doi:10.21203/rs.3.rs-4366047/v1

In this study, Laser-Induced Breakdown Spectroscopy (LIBS) technology was used to diagnose osteoporosis through nail analysis. The study focused on measuring calcium concentration in nails as an indicator of bone density and osteoporosis diagnosis. Samples were collected from a healthy individual and a person with osteoporosis from Al-Hillah Teaching Hospital. The results showed that healthy nails have higher calcium concentrations compared to nails affected by osteoporosis. LIBS technology is a powerful and accurate tool for analyzing the elemental composition of nails and identifying disease-related changes. Physicians can utilize this technique to improve their ability to diagnose and monitor osteoporosis and guide appropriate treatment.

Osteoporosis

Laser-induced breakdown spectroscopy (LIBS)

nail sample

Osteoporosis is a medical condition characterized by a loss of bone mass and deterioration of bone tissue, leading to increased bone fragility and a higher risk of fractures. It is a common condition, particularly among older individuals, and it affects both men and women [1]. The exact cause of osteoporosis is often multifactorial and can be influenced by various factors, including age, gender, hormonal changes, genetic predisposition, lifestyle choices, and certain medical conditions or medications. Women are at a higher risk, especially after menopause, due to a decrease in estrogen levels, which plays a protective role in maintaining bone density [2].

LIBS stands for Laser-Induced Breakdown Spectroscopy. It is an analytical technique used to determine the elemental composition of a sample [3]. LIBS works by focusing a high-energy laser beam onto the surface of the sample, causing the material to undergo plasma formation. This plasma emits light, and the emitted light is analyzed to determine the elemental composition of the sample [4].

When the laser beam interacts with the sample, it vaporizes and ionizes the surface material, creating a high-temperature plasma [5]. The plasma contains excited atoms and ions that emit characteristic light at specific wavelengths, which correspond to the elemental composition of the sample [6].

The emitted light is collected and passed through a spectrometer, which disperses the light into its different wavelengths [7]. The spectrometer then measures the intensity of the emitted light at each wavelength, producing a spectrum[8]. By analyzing the spectrum, scientists can identify the elements present in the sample and determine their concentrations [9]. The idea behind using LIBS for osteoporosis analysis is that changes in the elemental composition of bone, particularly calcium and phosphorus levels may indicate variations in bone mineral density (BMD) and the presence of osteoporosis [10]. By analyzing the emitted light spectrum from the plasma, researchers aim to identify and quantify the elemental composition of the bone, providing insights into its density and mineral content [11].

LIBS has several advantages as an analytical technique. It is fast, non-destructive, and requires little to no sample preparation [12]. It can analyze a wide range of materials, including solids, liquids, and gases. LIBS is used in various fields, including environmental monitoring, industrial quality control, archaeology, and forensics [13].

Passively Q-switch Nd:YAG with fundamental wavelength 1064 nm was employed at 100 mJ laser pulse energy and 10 ns pulse width. The laser radiations were focused via (100 mm) double-sided convex quartz lens onto a certain location on the nail sample to produce the plasma, using an optical quartz convex lens with (5 mm) focal length.

The test sample was fixed on a base of laser holder. The light emitted by the plasma plume was collected by a miniature lens fixed inside the head of multimode silica fiber optic. This fiber optic was located at a suitable distance relative to the laser generated plasma plume. The plasma emission was collected at 45◦ angle as an optimum angle relative to the nail. The plasma emission was transmitted through fiber optics to a high-resolution spectrometer.

The LIBS spectrum of human fingernail has been recorded for both injured and healthy samples in the spectral region of 180–800 nm. The recorded spectrum shown in Fig. 1 reveals the presence of multiple atomic lines that correspond to the elements present in the injured nail sample. These atomic lines were identified using spectral data from the NIST (National Institute of Standards and Technology). In Fig. 2, the detected elements in the healthy nail sample are displayed alongside their respective wavelengths. The dominant element is calcium (Ca), and there are also additional elements present, including potassium (K), phosphorus (P), magnesium (Mg), sodium (Na), iron (Fe), oxygen (O), titanium (Ti), and lead (Pb).

The plasma parameters (electron temperature and electron density) for the nail samples mentioned in Table 1 and Table 2 were calculated for a single spectral line using Eq. 1 and Eq. 2, respectively. The calculation of these parameters suggests the presence of an equilibrium plasma.

\({T_e}=\frac{{({E_2} - {E_1})}}{{k\ln (\frac{{I\lambda }}{{{A_{ki}}{g_k}}})}}\) ------------- (1)
\({n_e} \geqslant 1.6x{10^{12}}.{T_e}^{{1/2}}.{(\Delta E)^3}\) ---------------- (2)

Whereas: -

I: represents the intensity of the line

λ: Wavelength

g_k: represents the statistical weight

A_ki: probability of transition

K: Boltzmann constant

E₁: Lower energy level

E₂: upper energy level

Table .1 Spectral parameters of infected nail elements for sample S1

element	wavelength	NIST	intensity	E_k	E_i	A_ki	g_k	KT_e	n_e cm^− 3	RTe	Rne
CaII	315.99	315.887	55.339	7.047	3.123	3.1e + 08	4	4077.099	6.1728E + 15	3856.260	4.837E + 15
CaII	317.55	317.933	62.529	7.049	3.150	3.6e + 08	6	3901.642	5.9241E + 15
CaII	422.87	422.673	118.36	2.932	0.00	2.18e + 08	3	3590.040	2.4164E + 15
KI	307.8	307.500	84.903	27.176	23.145	4.30e + 07	5	5188.979	7.5492E + 15	5290.269	6.20E + 15
KII	358.8	358.660	123.89	26.706	23.250	2.52e + 07	3	5391.558	4.8494E + 15	5290.269	6.20E + 15
MgI	383.78	383.829	321.31	5.945	2.716	1.61e + 08	7	4108.663	3.4528E + 15	4108.663	3.4528E + 15
PII	465.82	465.831	88.113	15.514	12.853	2.1e + 07	7	3773.535	1.8519E + 15	3773.535	1.8519E + 15
Cu II	224.5	224.426	54.221	0.000	3.522	1.85e + 06	4	9997.217	6.9892E + 15	9997.217	6.9892E + 15
FeII	392.5	392.808	367.08	3.211	6.366	5.64e + 06	9	6243.26	3.9703E + 15	6243.26	3.9703E + 15
TiII	498.12	498.9134	104.2	1.980	4.465	3.70e + 07	5	5038.94	2.9247E + 15	5038.94	2.9247E + 15
PbII	406.95	406.213	108.93	2.660	5.717	9.2e + 07	3	3526.02	1.487E + 15	3526.02	1.487E + 15
O II	419.86	419.670	188.7	28.512	31.465	3.56e + 07	2	4060.70	2.921E + 15	4060.70	2.921E + 15

Table.2 Spectral parameters of Healthy nail elements for sample S2

element	wavelength	NIST	intensity	E_k	E_i	A_ki	g_k	Te	ne	RTe	Rne
CaII	315.96	315.887	59795	7.047	3.123	3.1e + 08	4	10883.59	9.87E + 15	6434.793	5.67E + 15
CaI	317.49	317.933	52.342	7.049	3.150	3.6e + 08	6	3842.65	3.1E + 15
CaI	370.74	370.603	98.88	6.467	3.123	8.8e + 07	2	4578.14	4.04E + 15
KI	310.76	310.179	86.956	3.996	0.00	1.62e + 04	4	53020.17	9.81E + 15	28724.24	7.05E + 15
KII	361.85	361.849	85.114	23.573	20.147	8.14e + 07	3	4428.31	4.28E + 15	28724.24	7.05E + 15
MgII	280.44	280.270	231.8	4.422	0.000	2.57e + 08	2	5717.47	1.04E + 15	5717.47	1.04E + 15
PI	213.16	213.546	50.004	7.212	1.408	2.11e + 07	4	7503.145	2.64E + 15	7503.145	2.64E + 16
Cu II	224.5	224.426	200.4	2.104	5.522	1.85e + 06	4	12558.32	7.15982E + 15	12558.32	7.15982E + 15
Fe II	240.2	240.349	136.77	7.7066	10.863	1.1e + 07	12	6747.360	4.13298E + 15	6747.360	4.13298E + 15
OII	419.9	419.670	171.7	28.512	31.465	3.56e + 07	2	2899.43	1.3221E + 15	2899.43	1.3221E + 15
TiII	498.5	498.913	17.78	1.980	4.465	3.70e + 07	5	3945.04	2.856E + 15	3945.04	2.856E + 15
PbII	406.82	406.213	85.669	2.660	5.7117	9.2e + 07	3	4970.01	2.9046E + 15	4970.01	2.9046E + 15

Figure (1) Emission spectrum of an infected nail sample (S1)

Figure (2) Emission spectrum of a healthy nail sample (S2)

After performing calculations to determine the plasma concentration of each spectral line corresponding to different elements, these concentrations are combined to obtain the total plasma concentration for each element. By comparing the concentration of a specific element to the sum of concentrations of all elements, the proportional ratio of that element within the overall emission spectrum can be calculated. This ratio is then multiplied by 100 to express it as a percentage.

The results of the analysis revealed that the percentage of calcium in the nail samples was 8.95% for the healthy condition and 6.4% for the injured condition. These findings demonstrate that the LIBS technique is suitable for nail analysis, as it provides acceptable results in determining the composition and concentration of elements in the samples

.

Table 3

Calculating the concentration of each spectral line for healthy and infected nail elements
Pathological case	Sample	N_eT	Element	concentration
infected	S1	5.05E + 16	Ca	28
			K	24
			Mg	6.8
			P	3.6
			Cu	13
			Fe	7.8
			O	5.79
			Ti	5.78
			Pb	2.9
healthy	S2	1.58E + 17	Ca	32
			K	26
			Mg	1.9
			P	4.9
			Cu	13
			Fe	7.7
			O	2.4
			Ti	5.3
			Pb	5.4

The application of the LIBS (Laser-Induced Breakdown Spectroscopy) technique has demonstrated its efficacy and suitability for the analysis of nail samples. This technique allows for the precise determination of the elemental composition and concentrations within the nails in a rapid and accurate manner.

By employing the LIBS technique, it becomes possible to calculate the plasma concentrations associated with each specific spectral line, providing valuable data on the element of interest. These concentrations can then be summed to obtain the total plasma concentration for a particular element.

The proportional ratio of a specific element within the overall emission spectrum can be calculated by dividing the concentration of that element by the sum of the concentrations of all elements, and then multiplying the result by 100. This ratio represents the percentage contribution of the element to the overall spectrum.

The results obtained from the analysis of the nail samples indicate that calcium (Ca) is the dominant element. In the healthy condition, calcium accounts for approximately 8.95% of the overall emission spectrum, while in the injured condition, it constitutes around 6.4%.

Therefore, based on these findings, it can be concluded that the LIBS technique is a reliable and suitable method for nail analysis. Its ability to accurately determine the elemental composition and concentrations within the samples provides valuable insights into the chemical makeup of the nails, allowing for potential diagnostic applications and monitoring of nail health.

Author Contribution

Safa 50%Sami 25%Alaa 25%

Cherni, Imen, et al. "Diagnosis of osteoporosis by UV-visible fluorescence of hair in relation to calcium deficiency assessed by the LIBS technique." OSA Continuum 4.7, 2053-2059, (2021).‏
Skalny, Anatoly V., et al. "Medical application of Laser-Induced Breakdown Spectroscopy (LIBS) for assessment of trace element and mineral in biosamples: laboratory and clinical validity of the method." Journal of Trace Elements in Medicine and Biology, 127241, (2023).‏
Gaudiuso, Rosalba, et al. "Laser-induced breakdown spectroscopy for human and animal health: A review." Spectrochimica Acta Part B: Atomic Spectroscopy 152, 123-148, (2019).‏
Taranushenko, T. E., N. G. Kiseleva, and T. V. Ovchinnikova. "Methods of prevention of calcium deficiency in pediatric practice." Archives of Preventive Medicine 7.1 (2022): 001-005.‏
Bali, Varun, et al. "Quantitative analysis of human hairs and nails." Biophysical Reviews, 1-17, (2023).‏
S.Hamzaoui, R.Khleifia, N.Jaidane and Z.BenLakhdar, Lasers Med.Sci., 26, 79 (2011).
M. Bahreiou, Z.Hosseeinimakarem and S.H. Tavassoli, J.App. Phys., 112, 054701 (2012).
Martinez, Mauro, and Matthieu Baudelet. "Matrix-matched calibration material for zinc analysis of human nails by laser-induced breakdown spectroscopy." Spectrochimica Acta Part B: Atomic Spectroscopy 163, 105732, (2020).‏
Nakkach, Mohamed, et al. "In situ characterization of human fingernails by optical front-face fluorescence for the identification of primary hypothyroidism." Instrumentation Science & Technology , 1-15, (2023).‏
. Dover, Anna R., J. Alastair Innes, and Karen Fairhurst, eds. Macleod's Clinical Examination-E-Book. Elsevier Health Sciences, (2023).‏
Maghsoumi, Sahar, and Hamidreza Shirvani-Mahdavi. "Calcium evaluation of human fingernail using laser plasma spectroscopy by simultaneously applying addition and modified external standardizations." Journal of Theoretical and Applied Physics 12, 319-326, (2018).‏
Hu, Zhenlin, et al. "A review of calibration-free laser-induced breakdown spectroscopy." TrAC Trends in Analytical Chemistry 152, 116618, (2022).‏
Strømme, Märta, et al. "Calcium and Silicon Delivery to Artificial and Human Nails from Nail Polish Formulations." Cosmetics 7.1, 15, (2020).

No competing interests reported.

Utilizing Laser-Induced Breakdown Spectroscopy (LIBS) of the nail for the detection of osteoporosis

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Abstract

Figures

Introduction

Experimental setup

Results and Discussion

Conclusion

Declarations

Author Contribution

References

Additional Declarations

Status:

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