Detection of living cervical cancer cells by transient terahertz spectroscopy

Black phosphorus enabled non-invasive protein detection with electromagnetic induction well terahertz biosensor chips

Terahertz biosensors are employed to detect proteins in cancer cells to facilitate early diagnosis and monitoring of cancer treatments. By optimizing the design and functionality of black phosphorus-based sensors, it is possible to enhance their sensitivity and specificity for specific cancer biomarkers, leading to more accurate diagnostic outcomes. The application of the externally applied magnetic field and the 455 nm continuous-wave laser further augments the sensitivity of cellular responses to THz waves, with magnetic influences typically surpassing those of light fields by 10%-80%. Our results examine the photonic properties of black phosphorus, improve its interaction with terahertz waves, and create prototypes that can selectively identify proteins associated with cancer cells. Additionally, the stability and reproducibility of these sensors have been greatly improved, boosting their potential for widespread use in clinical environments.

A new horizon for neuroscience: terahertz biotechnology in brain research

Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences. In this article, we review the development of terahertz biotechnology and its applications in the field of neuropsychiatry. Available evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease, cerebrovascular disease, glioma, psychiatric disease, traumatic brain injury, and myelin deficit. In vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric diseases. Although the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood, the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic applications. However, the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical applications. This review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.

Effect of terahertz radiation on cells and cellular structures

The paper presents the results of modern research on the effects of electromagnetic terahertz radiation in the frequency range 0.5-100 THz at different levels of power density and exposure time on the viability of normal and cancer cells. As an accompanying tool for monitoring the effect of radiation on biological cells and tissues, spectroscopic research methods in the terahertz frequency range are described, and attention is focused on the possibility of using the spectra of interstitial water as a marker of pathological processes. The problem of the safety of terahertz radiation for the human body from the point of view of its effect on the structures and systems of biological cells is also considered.

Detection of optical properties of chiral substances by a photoconductive THz polarization detector

Chiral enantiomers have significant differences in biochemical functions. The use of THz wave polarization detection to characterize the optical properties of chiral substances is of great significance to the development of life science and the identification and application of chiral substances. However, the traditional polarization detection procedures of THz waves are complex, which limits the study of chiral substances. Herein, we proposed a high-sensitivity THz polarization detector, which can simultaneously obtain the change information of amplitude, phase, and polarization state through a single measurement. The optical rotation and elliptical angle of solid and liquid D/L-Glutamic acid 5-methyl ester in the THz band are studied. Then it is verified that anisotropic interference may occur in the preparation of solid samples. Finally, the effects of sample content and thickness on polarization are obtained. The experimental results show that different chirality has the opposite effect on the state of polarization, and the difference between chiral enantiomers can be detected by this method. This work is of great significance for understanding the optical properties of chiral substances and promoting the development of chiral recognition.

Detection of food additives based on an integrated self-injected metasurface microfluidic sensor

Advanced sensing equipment exhibits high sensitivity and reliability in detecting food additives, enabling the practical assessment of the safety of processed foods. Currently, chemical detection methods are commonly utilized for identifying food additives. However, these approaches tend to be intricate and time-consuming. In this study, we designed and fabricated an integrated terahertz microfluidic sensor, which achieves high sensitivity by incorporating a metasurface within the microfluidic chip. The metasurface comprises metal wires and split-ring resonators, with three optional sensing sites within the frequency domain of 0.1-1.2 THz, thereby enhancing the reliability of the sensor. Additionally, the use of a self-injection micropump improves the stability of the liquid flow rate, preventing experimental errors caused by manual injection. Utilizing this sensor, we conducted concentration sensing experiments on potassium sorbate and sodium benzoate solutions, successfully identifying sugar-containing and sugar-substituted beverages with high sensitivity and rapid sensing speed. The average sensitivity of the sensor is 152.8 GHz·RIU-1. The results of this study provide a feasible method for the development of microfluidic metasurface sensors.

Cervical Cancer Detection Techniques: A Chronological Review

Cervical cancer is known as a major health problem globally, with high mortality as well as incidence rates. Over the years, there have been significant advancements in cervical cancer detection techniques, leading to improved accuracy, sensitivity, and specificity. This article provides a chronological review of cervical cancer detection techniques, from the traditional Pap smear test to the latest computer-aided detection (CAD) systems. The traditional method for cervical cancer screening is the Pap smear test. It consists of examining cervical cells under a microscope for abnormalities. However, this method is subjective and may miss precancerous lesions, leading to false negatives and a delayed diagnosis. Therefore, a growing interest has been in shown developing CAD methods to enhance cervical cancer screening. However, the effectiveness and reliability of CAD systems are still being evaluated. A systematic review of the literature was performed using the Scopus database to identify relevant studies on cervical cancer detection techniques published between 1996 and 2022. The search terms used included "(cervix OR cervical) AND (cancer OR tumor) AND (detect* OR diagnosis)". Studies were included if they reported on the development or evaluation of cervical cancer detection techniques, including traditional methods and CAD systems. The results of the review showed that CAD technology for cervical cancer detection has come a long way since it was introduced in the 1990s. Early CAD systems utilized image processing and pattern recognition techniques to analyze digital images of cervical cells, with limited success due to low sensitivity and specificity. In the early 2000s, machine learning (ML) algorithms were introduced to the CAD field for cervical cancer detection, allowing for more accurate and automated analysis of digital images of cervical cells. ML-based CAD systems have shown promise in several studies, with improved sensitivity and specificity reported compared to traditional screening methods. In summary, this chronological review of cervical cancer detection techniques highlights the significant advancements made in this field over the past few decades. ML-based CAD systems have shown promise for improving the accuracy and sensitivity of cervical cancer detection. The Hybrid Intelligent System for Cervical Cancer Diagnosis (HISCCD) and the Automated Cervical Screening System (ACSS) are two of the most promising CAD systems. Still, deeper validation and research are required before being broadly accepted. Continued innovation and collaboration in this field may help enhance cervical cancer detection as well as ultimately reduce the disease's burden on women worldwide.

Detection of the minimum concentrations of α-lactose solution using high-power THz-ATR spectroscopy

Terahertz (THz) technology has emerged as a promising tool for the qualitative and quantitative identification of markers containing major diseases, enabling early diagnosis and staged treatment of diseases. Nevertheless, the detection of water-containing biological samples is facing significant challenges due to limitations in high-power THz radiation sources and high-sensitivity detection devices. In this paper, we present a designed and constructed set of Terahertz-Attenuated Total Reflection (THz-ATR) spectrometer for high-sensitivity detection of liquid biological samples, which can dynamically maintain the signal-to-noise ratio (SNR) of THz detection signal of liquid biological samples at 40-60 dB. Our high-power THz-ATR spectroscopy can identify and quantitatively detect α-lactose aqueous solution with a minimum concentration of 0.292 mol/L. Moreover, we observed that the rate of change in the absorption peak position varied greatly between high and low concentration samples. Our high-power, high-sensitivity THz-ATR spectroscopy detection provides a rapid, accurate, and low-cost method for detecting disease markers such as blood and urine indicators. Additionally, this approach offers new perspectives for the refinement and in-depth detection of biomedical samples.

Revolutionary approaches for cancer diagnosis by terahertz-based spectroscopy and imaging

Most tumors are easily missed and misdiagnosed due to the lack of specific clinical signs and symptoms in the early stage. Thus, an accurate, rapid and reliable early tumor detection method is highly desirable. The application of terahertz (THz) spectroscopy and imaging in biomedicine has made remarkable progress in the past two decades, which addresses the shortcomings of existing technologies and provides an alternative for early tumor diagnosis. Although issues such as size mismatch and strong absorption of THz waves by water have set hurdles for cancer diagnosis by THz technology, innovative materials and biosensors in recent years have led to possibilities for new THz biosensing and imaging methods. In this article, we reviewed the issues that need to be solved before THz technology is used for tumor-related biological sample detection and clinical auxiliary diagnosis. We focused on the recent research progress of THz technology, with an emphasis on biosensing and imaging. Finally, the application of THz spectroscopy and imaging for tumor diagnosis in clinical practice and the main challenges in this process were also mentioned. Collectively, THz-based spectroscopy and imaging reviewed here is envisioned as a cutting-edge approach for cancer diagnosis.

Quantitative analysis of aqueous biomolecular mixtures by THz spectroscopy based on high-power LiNbO3 radiation source

The rapid and accurate identification of the types and contents of early pathological markers by THz technology are of particular importance for the prevention and treatment of major diseases. Nevertheless, these markers usually contain interference from water and other non-target molecules, resulting in low signal-to-noise ratio (SNR) and making identification and quantitative analysis difficult. Here, based on THz spectroscopy from a high-power THz source radiated by LiNbO₃, we perform quantitative and real-time THz detection of mixtures (α-lactose monohydrate and 4-aminobenzoic acid) in liquids. The results demonstrate that the absorption spectra of the aqueous biomolecular mixtures exhibit an accumulation of THz features of each pure product, i.e., the amplitude of the absorption peaks is proportional to the mixing ratio, while the corresponding absorption baseline increases with decreasing concentration. Furthermore, the content of the target substance can be calculated from the linear relationship between the absorption spectra of pure and mixed samples. This technology will support the future application of THz-TDS in early disease diagnosis under complex states and environments.

Studying the genotoxic effects of high intensity terahertz radiation on fibroblasts and CNS tumor cells

The data is obtained on the effect of high-intensity pulses of terahertz (THz) radiation with a broad spectrum (0.2-3 THz) on cell cultures. We have evaluated the threshold exposure parameters of THz radiation causing genotoxic effects in fibroblasts. Phosphorylation of histone H2AX at Ser 139 (γH2AX) was chosen as a marker for genotoxicity and a quantitative estimation of γH2AX foci number in fibroblasts was performed after cell irradiation with THz pulses for 30 min. No genotoxic effects of THz radiation were observed in fibroblasts unless peak intensity and electric field strength exceeded 21 GW cm-2 and 2.8 MV cm-1 , respectively. In tumor cell lines (neuroblastoma (SK-N-BE (2)) and glioblastoma (U87)), exposure to THz pulses with peak intensity of 21 GW cm-2 for 30 min caused no morphological changes as well as no statistically significant increase in histone phosphorylation foci number.

Quantitative detection of THz-ATR spectra of aqueous samples under strong-field terahertz wave

Owing to the characteristics of THz wave, the terahertz time-domain spectral (THz-TDS) system has potentials in the field of biological macromolecule detection. However, water with strong absorption effect on THz wave exists in most biological detection, so the research focus in this field is to study aqueous samples. In view of these, THz spectroscopy system has research value for qualitative and quantitative detection of α-lactose and its water-containing samples. This research used a THz-TDS system with LiNbO₃ crystal to generate strong THz wave that was used to test 0.29 mmol α-lactose samples with water content of 15 μL-930 μL by using attenuating total reflection (ATR) prism. The absorption peak at 0.53 THz is detected, and with the increase of water content, the curve of absorption spectrum is observed to move up on the whole. This research has a guiding role for the test and improvement of water content limit in this field.

Experimental Detection and Simulation of Terahertz Spectra of Aqueous L-Arginine

Terahertz (THz) wave is a good candidate for biological sample detection, because vibration and rotation energy levels of biomolecule are in THz band. However, the strong absorption of THz wave by water in biological samples hinders its development. In this paper, a method for direct detection of THz absorption spectra of L-arginine suspension was proposed by using a strong field THz radiation source combined with a polyethylene cell with micrometer thickness in a THz time-domain spectroscopy system. And the THz absorption spectrum of L-arginine solution was simulated by the density functional theory and the simulation result is in good agreement with the experimental results. Finally, the types of chemical bond interaction that cause the absorption peak are identified based on the experimental and simulation results. This work paves a way to investigate the THz absorption spectra and intramolecular interactions of aqueous biological samples.

Effect of THz spectra of L-Arginine molecules by the combination of water molecules

Most biomolecules are biologically active only in water; hence, it is worth investigating whether THz spectra of biomolecules are affected by the combination of water molecules and biomolecules. In this report, by combining the sample cell with the THz-TDS system, the THz spectra of L-Arginine crystal as well as its hydrate and aqueous solution are measured. The experimental results show that L-Arginine crystal and its hydrate share the same three absorption peaks at 0.99, 1.46, and 1.7 THz, respectively. But the trend of characteristic absorption spectrum of L-arginine solution is almost identical to that of free water. Because the contents of free water and hydrated water are different in many diseased and normal tissues, the diseased tissues can be detected according to the difference in THz spectral information. The proposed approach provides a reliable means for the detection of pathological changes of active molecules and tissues.

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L-Arginine crystal and its hydrate have the same three absorption peaks

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L-Arginine solution and free water have the same trend of absorption spectra

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The increment of water volume in the sample, the absorption baseline is rising

Recent advancements in optical biosensors for cancer detection

Optical biosensors are rapid, real-time, and portable, have a low detection limit and a high sensitivity, and have a great potential for diagnosing various types of cancer. Optical biosensors can detect cancer in a few million malignant cells, in comparison to conventional diagnosis techniques that use 1 billion cells in tumor tissue with a diameter of 7 nm-10 nm. Current cancer detection methods are also costly, inconvenient, complex, time consuming, and require technical specialists. This review focuses on recent advances in optical biosensors for early detection of cancer. It is primarily concerned with advancements in the design of various biosensors using resonance, scattering, chemiluminescence, luminescence, interference, fluorescence, absorbance or reflectance, and various fiber types. The development of various two-dimensional materials with optical properties such as biocompatibility, field enhancement, and a higher surface-to-volume ratio, as well as advancements in microfabrication technologies, have accelerated the development of optical sensors for early detection of cancer and other diseases. Surface enhanced Raman spectroscopy technology has the potential to detect a single molecule with high specificity, and terahertz waves are a recently explored technology for cancer detection. Due to the low electromagnetic interference, small size, multiplexing, and remote sensing capabilities of optical fiber-based platforms, they may be a driving force behind the rapid development of biosensors. The advantages and disadvantages of existing and future optical biosensor designs for cancer detection are discussed in detail. Additionally, a prospect for future advancements in the development of optical biosensors for point-of-care and clinical applications is highlighted.

A Review of Feasible Applications of THz Waves in Medical Diagnostics and Treatments

Introduction: Terahertz (THz) waves with frequencies in the range of 0.1 to 10 THz are electromagnetic radiation with growing applications in various fields of science and technology. Attractive features of this radiation have brought out many novel possibilities for medical diagnostics and treatments with considerable advantages compared to other conventional methods. Methods: In this paper, we present a review of more recent reports on practical applications of THz radiation for diagnostic, biosensing and clinical treatments. The review includes the diagnosis of breast, skin, mouth, cervical, lungs, small intestine, prostate, colon, and stomach cancers, the evaluation of biomolecules, the detection of genetic mutations, the determination of burn depth, the diagnosis of tooth decay, diabetes, and emotional-psychological states, the evaluation of corneal water to diagnose visual diseases, and wound healing monitoring. Further, it embraces the use of THz therapy in reducing the size of the tumor, treating skin cancer, and healing burn wounds, cardiovascular disease, corneal epithelium, angina, and THz heating. Results: This review has emphasized the capabilities of THz waves as a novel tool for future clinical diagnostics and treatments. Conclusion: The paper provides a comprehensive understanding of the feasible potential application of THz waves for clinical purposes and its advantages in comparison with other conventional tools.

Novel Terahertz Spectroscopy Technology for Crystallinity and Crystal Structure Analysis of Cellulose

Crystallinity is an essential indicator for evaluating the quality of fiber materials. Terahertz spectroscopy technology has excellent penetrability, no harmful substances, and commendable detection capability of absorption characteristics. The terahertz spectroscopy technology has great application potential in the field of fiber material research, especially for the characterization of the crystallinity of cellulose. In this work, the absorption peak of wood cellulose, microcrystalline cellulose, wood nano cellulose, and cotton nano cellulose were probed in the terahertz band to calculate the crystallinity, and the result compared with XRD and FT-IR analysis. The vibration model of cellulose molecular motion was obtained by density functional theory. The results showed that the average length of wood cellulose (WC) single fiber was 300 μm. The microcrystalline cellulose (MCC) was bar-like, and the average length was 20 μm. The cotton cellulose nanofiber (C-CNF) was a single fibrous substance with a length of 50 μm, while the wood cellulose nanofiber (W-CNF) was with a length of 250 μm. The crystallinity of cellulose samples in THz was calculated as follows: 73% for WC, 78% for MCC, 85% for W-CNF, and 90% for C-CNF. The crystallinity values were obtained by the three methods which were different to some extent. The absorption peak of the terahertz spectra was most obvious when the samples thickness was 1 mm and mixed mass ratio of the polyethylene and cellulose was 1:1. The degree of crystallinity was proportional to the terahertz absorption coefficients of cellulose, the five-movement models of cellulose molecules corresponded to the five absorption peak positions of cellulose.