Non-invasive bioassay of Cytokeratin Fragment 21.1 (Cyfra 21.1) protein in human saliva samples using immunoreaction method: An efficient platform for early-stage diagnosis of oral cancer based on biomedicine

Combining WO3@AuNPs with Poly(amidoamine) Allows Sensitive Electrochemical Detection of DR1 Based on Dual Signal Amplification

Down-regulator of transcription 1 (DR1) is considered as a biomarker of hashimoto's thyroiditis (HT), which is a risk factor for thyroid cancer. Here, a label-free electrochemical biosensor for DR1 detection was constructed based on polyamidoamine (PAMAM) polymer and the nanocomposite (WO3@AuNPs) composed of tungsten trioxide (WO3) and gold nanoparticles (AuNPs). WO3@AuNPs was obtained by combining monolayer WO3 nanosheets, which has high conductivity, and AuNPs. The modification of WO3@AuNPs can not only increase the conductivity of the electrode but also provide more active sites for signaling units, thus greatly improve the sensitivity of the sensor. The polymer PAMAM is biocompatible and non-immunogenic, and its end functional group can bind to the target molecules, providing them with more binding sites and thus improving the sensitivity of the sensor. Under optimal conditions, the label-free biosensor showed a good linear relationship between the logarithm of DR1 concentration and the impedance in the range of 10 fg ⋅ mL-1 to 100 ng ⋅ mL-1, with a detection limit as low as 0.3 fg ⋅ mL-1. Besides, this label-free electrochemical platform exhibited satisfactory selectivity and anti-interference capability in human serum samples. Therefore, this method has considerable potential in clinical detection of DR1.

Quantum dots: The trailblazers of early detection

Considering the robust awareness of early detection among oral clinicians and patients the increasing imposition of better methods for screening of oral precancerous/cancerous lesions has become imperative. Although histopathology has been considered the indispensable gold standard, it has its pros and cons, as sometimes the diagnosis is compromised with the variabilities subject to the histopathologist under concern. In the realm of oral healthcare, one pioneering trailblazer is making waves, which are 'quantum dots'. Quantum dots are poised to transform the landscape of oral precancer and cancer screening. These nano-sized semiconductor particles possess extraordinary properties that set them apart from conventional detection methods. Their ability to emit distinct wavelengths of light when excited makes them ideal candidates for early detection. The keywords were pitched in and the research literature from the last 15 years (2008-2022) was extirpated to find out the information that existed, the discrepancies and the void left for upcoming research. Its nature and ingenuity have given rise to a transformative approach that holds the potential to redefine the future of oral healthcare. With each breakthrough, we edge closer to a world where the early detection of oral precancerous/cancerous lesions becomes the norm rather than the exception.

Potential Diagnostic Value of Salivary Tumor Markers in Breast, Lung and Ovarian Cancer: A Preliminary Study

The aim of the study was to determine the content of tumor markers for breast, lung and ovarian cancer in saliva, as well as for benign diseases of the corresponding organs and in the control group, and to evaluate their diagnostic significance. Strictly before the start of treatment, saliva samples were obtained and the concentrations of tumor markers (AFP, NSE, HE4, CA15-3, CA72-4, CA125 and CEA) were determined using an enzyme immunoassay (ELISA). CA125 and HE4 were simultaneously determined to be in the blood serum of patients with ovarian cancer. The concentrations of salivary CEA, NSE, CA15-3, CA72-4 and CA125 of the control group were significantly lower than in oncological diseases; however, these tumor markers also increased in saliva with benign diseases. The content of tumor markers depends on the stage of cancer, and the presence of lymph node metastasis; however, the identified patterns are statistically unreliable. The determination of HE4 and AFP in saliva was not informative. In general, the area of potential use of tumor markers in saliva is extremely narrow. Thus, CEA may be diagnostic for breast and lung cancer, but not for ovarian cancer. CA72-4 is most informative for ovarian mucinous carcinoma. None of the markers showed significant differences between malignant and non-malignant pathologies.

Multifunctional AuNPs@HRP@FeMOF immune scaffold with a fully automated saliva analyzer for oral cancer screening

Delayed diagnosis of cancer-causing death is a worldwide concern. General diagnosis methods are invasive, time-consuming, and operation complicated, which are not suitable for preliminary screening. To address these challenges, the sensing platform based on immune scaffold and fully automated saliva analyzer (FASA) was proposed for oral cancer screening for the first time by non-invasive detection of Cyfra21-1 in saliva. Through one-step synthesis method with unique covalent and electrostatic adsorption strategy, AuNPs@HRP@FeMOF immune scaffold features multiple functions including antibody carrier, catalytic activity, and signal amplification. Highly integrated FASA with the immune scaffold provides automatic testing to avoid false-positive results and reduce pretreatment time without any user intervention. Compared with the commercial analyzer, FASA has comparable performance for Cyfra21-1 detection with a detection range of 3.1-50.0 ng/mL and R² of 0.971, and superior features in full automation, high integration, time saving and low cost. Oral cancer patients could be distinguished accurately by the platform with an excellent correlation (R² of 0.904) and average RSD (5.578%) without sample dilution. The proposed platform provides an effective and promising tool for cancer screening in point-of-care applications, which can be further extended for biomarker detection in universal body fluids, disease screening, prognosis review and homecare monitoring.

Use of Cysteamine and Glutaraldehyde Chemicals for Robust Functionalization of Substrates with Protein Biomarkers—An Overview on the Construction of Biosensors with Different Transductions

Currently, several biosensors are reported to confirm the absence/presence of an abnormal level of specific human biomarkers in research laboratories. Unfortunately, public marketing and/or pharmacy accessibility are not yet possible for many bodily fluid biomarkers. The questions are numerous, starting from the preparation of the substrates, the wet/dry form of recognizing the (bio)ligands, the exposure time, and the choice of the running buffers. In this context, for the first time, the present overview summarizes the pre-functionalization of standard and nanostructured solid/flexible supports with cysteamine (Cys) and glutaraldehyde (GA) chemicals for robust protein immobilization and detection of biomarkers in body fluids (serum, saliva, and urine) using three transductions: piezoelectrical, electrochemical, and optical, respectively. Thus, the reader can easily access and compare step-by-step conjugate protocols published over the past 10 years. In conclusion, Cys/GA chemistry seems widely used for electrochemical sensing applications with different types of recorded signals, either current, potential, or impedance. On the other hand, piezoelectric detection via quartz crystal microbalance (QCM) and optical detection by surface plasmon resonance (LSPR)/surface-enhanced Raman spectroscopy (SERS) are ultrasensitive platforms and very good candidates for the miniaturization of medical devices in the near future.

Emerging Biosensors for Oral Cancer Detection and Diagnosis—A Review Unravelling Their Role in Past and Present Advancements in the Field of Early Diagnosis

Oral cancer is a serious concern to people all over the world because of its high mortality rate and metastatic spread to other areas of the body. Despite recent advancements in biomedical research, OC detection at an early stage remains a challenge and is complex and inaccurate with conventional diagnostics procedures. It is critical to study innovative approaches that can enable a faster, easier, non-invasive, and more precise diagnosis of OC in order to increase the survival rate of patients. In this paper, we conducted a review on how biosensors might be an excellent tool for detecting OC. This review covers the strategies that use different biosensors to target various types of biomarkers and focuses on biosensors that function at the molecular level viz. DNA biosensors, RNA biosensors, and protein biosensors. In addition, we reviewed non-invasive electrochemical methods, optical methods, and nano biosensors to analyze the OC biomarkers present in body fluids such as saliva and serum. As a result, this review sheds light on the development of ground-breaking biosensors for the early detection and diagnosis of OC.

Malignancies and Biosensors: A Focus on Oral Cancer Detection through Salivary Biomarkers

Oral cancer is among the deadliest types of malignancy due to the late stage at which it is usually diagnosed, leaving the patient with an average five-year survival rate of less than 50%. The booming field of biosensing and point of care diagnostics can, in this regard, play a major role in the early detection of oral cancer. Saliva is gaining interest as an alternative biofluid for non-invasive diagnostics, and many salivary biomarkers of oral cancer have been proposed. While these findings are promising for the application of salivaomics tools in routine practice, studies on larger cohorts are still needed for clinical validation. This review aims to summarize the most recent development in the field of biosensing related to the detection of salivary biomarkers commonly associated with oral cancer. An introduction to oral cancer diagnosis, prognosis and treatment is given to define the clinical problem clearly, then saliva as an alternative biofluid is presented, along with its advantages, disadvantages, and collection procedures. Finally, a brief paragraph on the most promising salivary biomarkers introduces the sensing technologies commonly exploited to detect oral cancer markers in saliva. Hence this review provides a comprehensive overview of both the clinical and technological advantages and challenges associated with oral cancer detection through salivary biomarkers.

Electrochemical immunoplatform to assist in the diagnosis of oral cancer through the determination of CYFRA 21.1 biomarker in human saliva samples: Preparation of a novel portable biosensor toward non-invasive diagnosis of oral cancer

In this study, a novel, low-cost, and flexible paper-based electrochemical immunosensor was developed for the bioanalysis of Cyfra 21.1 biomarker in human saliva samples by using stabilization of synthesis Ag nano-ink on the surface of paper using pen-on-paper technology. The employed electrochemical techniques for the evaluation of immunoplatform performance were differential pulse voltammetry and chronoamperometry. Also, the prepared immunosensor showed great ability in the determination of Cyfra21.1 in human saliva specimens. Under the optimized conditions, the obtained linear range was from 0.0025 to 10 ng/mL, and the obtained LLOQ was 0.0025 ng/mL. The developed immunosensor is easy to prepare, sensitive, cost-effective, portable, and simple. So proposed immunoplatform can be an accomplished biodevice in clinical laboratories. The proposed paper-based immunosensor could be a hopefully new and cheap tool for the diagnosis of other biomarkers. Also, the prepared immunosensor showed great ability in the determination of Cyfra21.1 biomarker in human saliva specimens.

Chemical binding of molecular-imprinted polymer to biotinilated antibody: Utilization of molecular imprinting polymer as intelligent synthetic biomaterials toward recognition of carcinoma embryonic antigen in human plasma sample

In this study, a novel biosensor based on molecular imprinting polymer (MIP) methodology was fabricated toward recognition of carcinoembryonic antigen (CEA). For this purpose, poly (toluidine blue) (PTB) was electropolymerized on the surface of gold electrode in the absence and presence of CEA. So, the target molecules were entrapped into the imprinted specific cavities of MIP. Obtained results show that, the binding affinity of the MIP system was significantly higher than that of revealed for the nonimprinted polymer (NIP) system, MIP-based biosensor revealed linear response from (0.005 to 75 μg/L) and low limit of quantification of (0.005 μg/L) by using chronoamperometry technique, leading to CEA monitoring in real and clinical samples. Thus, a novel technique for rapid, simple, sensitive and affordable monitoring of CEA (LLOQ = 0.005 μg/L) has provided through developed biosensor. From a future perspective, moreover, this method can be considered as an applicable candidate in biomedical and clinical analysis for point-of-care usages.

Ultrasensitive biosensing platform based on yttria doped zirconia-reduced graphene oxide nanocomposite for detection of salivary oral cancer biomarker

Herein, we report results of the studies relating to the fabrication of yttria-doped zirconia-reduced graphene oxide nanocomposite (nYZR) based biosensing platform for detection of salivary CYFRA-21-1 biomarker. The nYZR nanocomposite was hydrothermally synthesized and amine-functionalized using 3-aminopropyl triethoxysilane (APTES). This functionalized nanocomposite (APTES/nYZR) was electrophoretically deposited (45 V; 3 min) onto pre-hydrolyzed indium tin oxide (ITO) coated glass substrate (APTES/nYZR/ITO) followed by biofunctionalization via covalent immobilization of the anti-CYFRA-21-1 antibodies (anti-CYFRA-21-1/APTES/nYZR/ITO). The synthesized nanomaterial and the fabricated electrodes were characterized to investigate crystal structure, morphology and electrochemical properties via X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. The fabricated biosensing electrode (BSA/anti-CYFRA-21-1/APTES/nYZR/ITO) has an operating shelf life of 56 days and can be used to detect salivary CYFRA-21-1 biomarker concentration as low as 7.2 pg mL^-1 with wide linear detection range of 0.01-50 ng mL^-1. This work opens new opportunities to explore the electrochemical behavior of nanostructured yttria stabilized zirconia (YSZ) and its composites at room temperature and its utility in developing biosensors and other electrochemical devices.