Flexible sensor based on conducting polymer and gold nanoparticles for electrochemical screening of HPV families in cervical specimens

Polymer-Based Electrochemical Sensors for the Diagnosis of Neurodegenerative Diseases

Acute and chronic neurodegenerative diseases (NDs), including multiple sclerosis (MS), Alzheimer's disease (AD), and Parkinson's disease (PD), are characterized by neurodegeneration, which is the gradual malfunction and damage of neurons and axons in the central nervous system. Improved clinical diagnostic workups and the development and tracking of successful disease-modifying treatments are made possible by detecting appropriate neurodegenerative disease (ND) biomarkers. Important biomarkers, such as Tau proteins, amyloid-β, and α-synucleins, are essential for precise identification but are often evaluated using time-consuming, expensive, and traditional techniques like polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Due to its exceptional selectivity and sensitivity, electrochemical biosensing has become a popular, low-cost substitute for more conventional diagnostic methods. Nanoparticles in biosensors are particularly noteworthy because they improve electron transport and aid in immobilizing biorecognition components. Conducting polymers have shown great potential in the field of electrochemical sensing. Conducting polymers have shown great potential in electrochemical sensing. Additionally, research has shown that polypyrrole, polyaniline, poly(3,4-ethylenedioxythiophene), and poly(thiophene) are often regarded as among the best conducting polymers for fabricating electrochemical sensors. Moreover, a hydrogel biosensor allows for the detection of many parameters simultaneously with real-time monitoring, allowing for more accurate and timely tracking of multiple indicators of a patient. Hydrogel nano(bio)composite sensors that use electrochemical transduction methods to detect analytes are also available. Hydrogel-based polymer sensors for early-stage neurodegenerative diagnosis are examined in this review in a novel way. Afterward, we reviewed electrochemical sensors developed for detecting biomarkers related to diseases, including multiple sclerosis, Alzheimer's, Parkinson's, and Huntington's. There have also been developments devised to enhance efficacy of electrochemical diagnostic tools to address their limitations. In this respect, we have also reviewed many polymers used in electrochemical diagnosis of neurological disorders. Finally, we have also evaluated the limits and prospects of clinical trials involving these electrochemical means of diagnoses.

Human papilloma virus (HPV) mediated cancers: an insightful update

Human papillomavirus (HPV), a DNA virus, is a well-documented causative agent of several cancers, including cervical, vulvar, vaginal, penile, anal, and head & neck cancers. Major factors contributing to HPV-related cancers include persistent infection and the oncogenic potential of particular HPV genotypes. High-risk HPV strains, particularly HPV-16 and HPV-18, are responsible for over 70% of cervical cancer cases worldwide, as well as a significant proportion of other genital and head and neck cancers. At the molecular level, the oncogenic activity of these viruses is driven by the overexpression of E6 and E7 oncoproteins. These oncoproteins dysregulate the cell cycle, inhibit apoptosis, and promote the accumulation of DNA damage, ultimately transforming normal cells into cancerous ones. This review aims to provide a comprehensive overview of the recent advances in HPV-related cancer biology and epidemiology. The review highlights the molecular pathways of HPV-driven carcinogenesis, focusing on the role of viral oncoproteins in altering host cell targets and disrupting cellular signalling pathways. The review explores the therapeutic potential of these viral proteins, and discusses current diagnostic and treatment strategies for HPV-associated cancers. Furthermore, the review highlights the critical role of HPV in the development of various malignancies, emphasizing the persistent challenges in combating these cancers despite advancements in vaccination and therapeutic strategies. We also emphasize recent breakthroughs in utilizing biomarkers to monitor cancer therapy responses, such as mRNAs, miRNAs, lncRNAs, proteins, and genetic markers. We hope this review will serve as a valuable resource for researchers working on HPV, providing insights that can guide future investigations into this complex virus, which continues to be a major contributor to global morbidity and mortality.

Electrochemical detection of cervical cancer biomarkers

Cervical cancer (CC) is the fourth most common cancer among women worldwide, following breast, colorectal, and lung cancers. Each year, it accounts for approximately 600,000 new cases and 340,000 deaths. Early-stage cervical cancer is treatable with surgery and chemoradiotherapy (CCRT). However, treatment for metastatic cervical cancer is limited, with bevacizumab combined with chemotherapy being one of the few options, though survival rates remain low. Currently, the diagnosis of cervical cancer primarily relies on Pap smears and colposcopy. Although these methods are essential for detection, they are costly, labor-intensive, and require significant resources. Therefore, there is an urgent need to identify effective biomarkers that can detect cervical cancer at an early stage, improving both the accuracy of diagnosis and the efficacy of treatment. Although numerous cervical cancer biomarkers have been identified for the cervical cancer thanks to advances in technology. In recent times, electrochemical methods have proven to be particularly effective in cervical cancer detection. In this paper, we reviewed the important cervical cancer biomarkers and their detection through electrochemical biosensors, which offer advantages such as higher sensitivity, affordability, and ease of analysis. Furthermore, we discussed the limitations and future prospects of electrochemical biosensors in this field.

Nanotechnology and nanobots unleashed: pioneering a new era in gynecological cancer management - a comprehensive review

INTRODUCTION

Gynecological cancers, such as ovarian, cervical, and endometrial malignancies, are notoriously challenging due to their intricate biology and the critical need for precise diagnostic and therapeutic approaches. In recent years, groundbreaking advances in nanotechnology and nanobots have emerged as game-changers in this arena, offering the promise of a new paradigm in cancer management. This comprehensive review delves into the revolutionary potential of these technologies, showcasing their ability to transform the landscape of gynecological oncology.

METHODOLOGY

A systematic literature search spanning from March 2005 to August 2024 was conducted using major databases such as PubMed, Google Scholar, and Scopus. Keywords included "nanotechnology," "nanobots," "gynecological cancers," "ovarian cancer," "cervical cancer," and "endometrial cancer." Relevant articles published in English were selected based on their focus on nanotechnology and nanobots in the diagnosis, treatment, and management of gynecological cancers. The findings were synthesized to present a coherent overview of how nanotechnology and nanobots are reshaping gynecological cancer management. The review highlights key innovations, current applications, and future directions for research and clinical implementation.

CONCLUSION

The integration of nanotechnology and nanobots in gynecological cancer management represents a groundbreaking shift in the field. Recent advancements in nanoscale materials and robotic technology offer unprecedented opportunities for precision diagnosis, targeted drug delivery, and innovative therapeutic approaches. Despite promising developments, challenges such as biocompatibility, safety, and regulatory issues remain. Continued research and clinical trials are essential to overcome these hurdles and fully realize the potential of nanotechnology and nanobots.

Polymeric Nanostructures Revolutionizing Cervical Cancer: Diagnostics, Therapeutics, and Theranostics

Cervical cancer is the fourth most common cancer among women. Despite recent advancements in diagnostics and therapeutics, this disease is still a formidable challenge to deal with. Conventional methods for detecting human papillomavirus infection and imaging the tissues face major hurdles due to a lack of signal specificity and obscured resolution respectively. Moreover, chemotherapeutics struggle against the development of multidrug resistance and rapid clearance. With their easily tunable properties, polymeric nanostructures present a promising avenue for rapid, specific, and efficient diagnostics and therapeutics. These nanostructures also serve as theranostic agents that integrate imaging modalities with therapeutic approaches concurrently. This review highlights various types of polymeric nanostructures that serve as biosensors for the detection and quantification of cervical cancer biomarkers and act as nanocarriers for transporting fluorophores, photosensitizers, drugs, and radiosensitizers to their target site of action.

Graphical Abstract

Capped Plasmonic Gold and Silver Nanoparticles with Porphyrins for Potential Use as Anticancer Agents-A Review

Photothermal therapy (PTT) and photodynamic therapy (PDT) are potential cancer treatment methods that are minimally invasive with high specificity for malignant cells. Emerging research has concentrated on the application of metal nanoparticles encapsulated in porphyrin and their derivatives to improve the efficacy of these treatments. Gold and silver nanoparticles have distinct optical properties and biocompatibility, which makes them efficient materials for PDT and PTT. Conjugation of these nanoparticles with porphyrin derivatives increases their light absorption and singlet oxygen generation that create a synergistic effect that increases phototoxicity against cancer cells. Porphyrin encapsulation with gold or silver nanoparticles improves their solubility, stability, and targeted tumor delivery. This paper provides comprehensive review on the design, functionalization, and uses of plasmonic silver and gold nanoparticles in biomedicine and how they can be conjugated with porphyrins for synergistic therapeutic effects. Furthermore, it investigates this dual-modal therapy's potential advantages and disadvantages and offers perspectives for future prospects. The possibility of developing gold, silver, and porphyrin nanotechnology-enabled biomedicine for combination therapy is also examined.

New bioelectrode based on graphene quantum dots-polypyrrole film and Concanavalin A for pathogenic microorganism detection

Infections caused by microorganisms are a public health problem worldwide. New biodetection systems are essential to diagnose with accuracy resulting in more effective treatment. In this work, we propose a ConA-conjugated graphene quantum dots and polypyrrole film-based biosensor for label-free detection of Candida albicans, Candida glabrata, Candida tropicalis, E. coli, B. subitilis, and S. aureus. We modified polypyrrole and graphene quantum dots (PPY-QDGs) with Concanavalin A (Con A) lectin. ConA is a glucose/mannose-specific lectin. The results showed that ConA lectin has the highest binding affinity for C. tropicalis and S. subtilis. PPY-GQDs-ConA binding profile revealed differential response for Candida spp (C. tropicalis > C. albicans > C. glabrata) and bacterial (B. subtilis > S. aureus > E. coli). The limits of detection (LOD) obtained were 1.42 CFU/mL for C. albicans, and 3.72 CFU/mL for C. glabrata. C. tropicalis yielded a LOD of 0.18 CFU/mL. The respective LODs for the evaluated bacteria were 0.39 CFU/mL for S. aureus, 0.72 CFU/mL for S. subtilis, and 2.63 CFU/mL for E. coli. The differential response obtained for the sensor can be attributed to the heterogeneous distribution of carbohydrates on the microorganism's surfaces. The proposed system based on a flexible substrate is effective for microbiological diagnosis.

Advances in DNA-based electrochemical biosensors for the detection of foodborne pathogenic bacteria

The detection of foodborne pathogenic bacteria is critical in preventing foodborne diseases. DNA-based electrochemical biosensors, with the merits of high sensitivity and short detection time, provide an effective detecting method for foodborne pathogens, attracting significant interest for the past few years. This review mainly describes the important research progress of DNA-based electrochemical biosensors for the detection of foodborne pathogenic bacteria through four perspectives: representative foodborne pathogens detection using electrochemical approaches, DNA immobilization strategies of aptamers, DNA-based signal amplification strategies used in electrochemical DNA sensors, and functional DNA used in electrochemical DNA sensors. Finally, perspectives and challenges are presented in this field. This review will contribute to DNA-based electrochemical biosensor in enhancing the nucleic acid signal amplification.

Gold nanoparticles-based biosensors: pioneering solutions for bacterial and viral pathogen detection-a comprehensive review

Gold Nanoparticles (AuNPs) have gained significant attention in biosensor development due to their unique physical, chemical, and optical properties. When incorporated into biosensors, AuNPs offer several advantages, including a high surface area-to-volume ratio, excellent biocompatibility, ease of functionalization, and tunable optical properties. These properties make them ideal for the detection of various biomolecules, including proteins, nucleic acids, and bacterial and viral biomarkers. Traditional methods for detecting bacteria and viruses, such as RT-PCR and ELISA, often suffer from complexities, time consumption, and labor intensiveness. Consequently, researchers are continuously exploring novel devices to address these limitations and effectively detect a diverse array of infectious pathogenic microorganisms. In light of these challenges, nanotechnology has been instrumental in refining the architecture and performance of biosensors. By leveraging advancements in nanomaterials and strategies of biosensor fabrication the sensitivity and specificity of biosensors can be enhanced, enabling more precise detection of pathogenic bacteria and viruses. This review explores the versatility of AuNPs in detecting a variety of biomolecules, including proteins, nucleic acids, and bacterial and viral biomarkers. Furthermore, it evaluates recent advancements in AuNPs-based biosensors for the detection of pathogens, utilizing techniques such as optical biosensors, lateral flow immunoassays, colorimetric immunosensors, electrochemical biosensors, and fluorescence nanobiosensors. Additionally, the study discusses the existing challenges in the field and proposes future directions to improve AuNPs-based biosensors, with a focus on enhancing sensitivity, selectivity, and their utility in clinical and diagnostic applications.

Nucleic acid-based electrochemical biosensors

Colorectal cancer, breast cancer, oxidative DNA damage, and viral infections are all significant and major health threats to human health, presenting substantial challenges in early diagnosis. In this regard, a wide range of nucleic acid-based electrochemical platforms have been widely employed as point-of-care diagnostics in health care and biosensing technologies. This review focuses on biosensor design strategies, underlying principles involved in the development of advanced electrochemical genosensing devices, approaches for immobilizing DNA on electrode surfaces, as well as their utility in early disease diagnosis, with a particular emphasis on cancer, leukaemia, oxidative DNA damage, and viral pathogen detection. Notably, the role of biorecognition elements and nanointerfaces employed in the design and development of advanced electrochemical genosensors for recognizing biomarkers related to colorectal cancer, breast cancer, leukaemia, oxidative DNA damage, and viral pathogens has been extensively reviewed. Finally, challenges associated with the fabrication of nucleic acid-based biosensors to achieve high sensitivity, selectivity, a wide detection range, and a low detection limit have been addressed. We believe that this review will provide valuable information for scientists and bioengineers interested in gaining a deeper understanding of the fabrication and functionality of nucleic acid-based electrochemical biosensors for biomedical diagnostic applications.

Advanced technologies towards improved HPV diagnostics

Persistent infection with high-risk types of human papillomaviruses (HPV) is a major cause of cervical cancer, and an important factor in other malignancies, for example, head and neck cancer. Despite recent progress in screening and vaccination, the incidence and mortality are still relatively high, especially in low-income countries. The mortality and financial burden associated with the treatment could be decreased if a simple, rapid, and inexpensive technology for HPV testing becomes available, targeting individuals for further monitoring with increased risk of developing cancer. Commercial HPV tests available in the market are often relatively expensive, time-consuming, and require sophisticated instrumentation, which limits their more widespread utilization. To address these challenges, novel technologies are being implemented also for HPV diagnostics that include for example, isothermal amplification techniques, lateral flow assays, CRISPR-Cas-based systems, as well as microfluidics, paperfluidics and lab-on-a-chip devices, ideal for point-of-care testing in decentralized settings. In this review, we first evaluate current commercial HPV tests, followed by a description of advanced technologies, explanation of their principles, critical evaluation of their strengths and weaknesses, and suggestions for their possible implementation into medical diagnostics.

Flexible genosensors based on polypyrrole and graphene quantum dots for PML/RARα fusion gene detection: A study of acute promyelocytic leukemia in children

Acute promyelocytic leukemia (APL) in children is associated with a favorable initial prognosis. However, minimal residual disease (MRD) follow-up remains poorly defined, and relapse cases are concerning due to their recurrent nature. Thus, we report two electrochemical flexible genosensors based on polypyrrole (PPy) and graphene quantum dots (GQDs) for label-free PML-RARα oncogene detection. Atomic force microscopy (AFM), scanning electron microscope (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used to characterize the technological biosensor development. M7 and APLB oligonucleotide sequences were used as bioreceptors to detect oncogenic segments on chromosomes 15 and 17, respectively. AFM characterization revealed heterogeneous topographical surfaces with maximum height peaks for sensor layers when tested with positive patient samples. APLB/Genosensor exhibited a percentage change in anode peak current (ΔI) of 423 %. M7/Genosensor exhibited a ΔI of 61.44 % for more concentrated cDNA samples. The described behavior is associated with the biospecific recognition of the proposed biosensors. Limits of detection (LOD) of 0.214 pM and 0.677 pM were obtained for APLB/Genosensor and M7/Genosensor, respectively. The limits of quantification (LOQ) of 0.648 pM and 2.05 pM were estimated for APLB/Genosensor and M7/Genosensor, respectively. The genosensors showed reproducibility with a relative standard deviation of 7.12 % for APLB and 1.18 % for M7 and high repeatability (9.89 % for APLB and 1.51 % for M7). In addition, genetic tools could identify the PML-RARα oncogene in purified samples, plasmids, and clinical specimens from pediatric patients diagnosed with APL with high bioanalytical performance. Therefore, biosensors represent a valuable alternative for the clinical diagnosis of APL and monitoring of MRD with an impact on public health.

Electrochemical nucleic acid sensors: Competent pathways for mobile molecular diagnostics

Electrochemical nucleic acid biosensor has demonstrated great promise in clinical diagnostic tests, mainly because of its flexibility, high efficiency, low cost, and easy integration for analytical applications. Numerous nucleic acid hybridization-based strategies have been developed for the design and construction of novel electrochemical biosensors for diagnosing genetic-related diseases. This review describes the advances, challenges, and prospects of electrochemical nucleic acid biosensors for mobile molecular diagnosis. Specifically, the basic principles, sensing elements, applications in diagnosis of cancer and infectious diseases, integration with microfluidic technology and commercialization are mainly included in this review, aiming to provide new insights and directions for the future development of electrochemical nucleic acid biosensors.

Glycated Hemoglobin Electrochemical Immunosensor Based on Screen-Printed Electrode

An electrochemical HbA1c sensor with high sensitivity and good specificity is proposed based on the electrochemical immune principle. The reproducibility and conductivity of the electrode are improved by depositing gold nanoparticles (AuNPs) on the surface of the screen-printed electrode (SPE). The HbA1c antibodies are immobilized on the surface of the modified electrode by adsorption to capture the HbA1c in the sample. The hindering effect of HbA1c on the electrode transfer reaction was exploited as the HbA1c detection mechanism. The electrode's properties were characterized by electrochemical impedance spectroscopy (EIS), and the measurement properties of the electrode were analyzed using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The experimental results show that the peak current signal of the electrochemical immunosensor produced a linear response to HbA1c in the concentration range of 20-200 μg/mL, a linear relationship coefficient of 0.9812, a detection limit of 15.5 µg/mL, and a sensitivity of 0.0938 µA/µg·mL^-1. The sensor delivered satisfactory repeatability, stability, and anti-interference performance. Due to its small size, high sensitivity, and wide linear detection range, it is expected to play a significant role in managing diabetes at home.

Genosensors as an alternative diagnostic sensing approaches for specific detection of various certain viruses: a review of common techniques and outcomes

Viral infections are responsible for the deaths of millions of people throughout the world. Since outbreak of highly contagious and mutant viruses such as contemporary sars-cov-2 pandemic, has challenged the conventional diagnostic methods, the entity of a thoroughly sensitive, specific, rapid and inexpensive detecting technique with minimum level of false-positivity or -negativity, is desperately needed more than any time in the past decades. Biosensors as minimized devices could detect viruses in simple formats. So far, various nucleic acid, immune- and protein-based biosensors were designed and tested for recognizing the genome, antigen, or protein level of viruses, respectively; however, nucleic acid-based sensing techniques, which is the foundation of constructing genosensors, are preferred not only because of their ultra-sensitivity and applicability in the early stages of infections but also for their ability to differentiate various strains of the same virus. To date, the review articles related to genosensors are just confined to particular pathogenic diseases; In this regard, the present review covers comprehensive information of the research progress of the electrochemical, optical, and surface plasmon resonance (SPR) genosensors that applied for human viruses' diseases detection and also provides a well description of viruses' clinical importance, the conventional diagnosis approaches of viruses and their disadvantages. This review would address the limitations in the current developments as well as the future challenges involved in the successful construction of sensing approaches with the functionalized nanomaterials and also allow exploring into core-research works regarding this area.

A Flexible Electrochemiluminescence Sensor Equipped With Vertically Ordered Mesoporous Silica Nanochannel Film for Sensitive Detection of Clindamycin

Fast, convenient, and highly sensitive detection of antibiotic is essential to avoid its overuse and the possible harm. Owing to enrichment effect and antifouling ability of ultrasmall nanochannels, the vertically ordered mesoporous silica nanochannel film (VMSF) has great potential in the development of the facile electrochemiluminescence (ECL) sensor for direct and sensitive analysis of antibiotics in complex samples. In this study, we demonstrated a flexible ECL sensor based on a cost-effective electrode covered with a VMSF for sensitive detection of clindamycin. Polyethylene terephthalate coated with indium tin oxide (PET-ITO) is applied as a flexible electrode to grow VMSF using the electrochemically assisted self-assembly (EASA) method. The negatively charged VMSF nanochannels exhibit significant enrichment toward the commonly used cationic ECL luminophores, tris(2,2-bipyridyl) dichlororuthenium (II) (Ru (bpy)₃²⁺). Using the enhanced ECL of Ru (bpy)₃²⁺ by clindamycin, the developed VMSF/PET-ITO sensor can sensitively detect clindamycin. The responses were linear in the concentration range of 10 nM–25 μM and in the concentration range of 25–70 μM. Owing to the nanoscale thickness of the VMSF and the high coupling stability with the electrode substrate, the developed flexible VMSF/PET-ITO sensor exhibits high signal stability during the continuous bending process. Considering high antifouling characteristic of the VMSF, direct analysis of clindamycin in a real biological sample, human serum, is realized.

Evolution of nucleic acids biosensors detection limit III

This review is an update of two previous ones focusing on the limit of detection of electrochemical nucleic acid biosensors allowing direct detection of nucleic acid target (miRNA, mRNA, DNA) after hybridization event. A classification founded on the nature of the electrochemical transduction pathway is established. It provides an overall picture of the detection limit evolution of the various sensor architectures developed during the last three decades and a critical report of recent strategies.

Designing DNA probe from HPV 18 and 58 in the E6 region for sensing element in the development of genosensor-based gold nanoparticles

The E6 region has higher protuberant probability annealing than consensus probe focusing on another region in the human papillomavirus (HPV) genome in terms of detection and screening method. Here, we designed the first multiple virus single-stranded deoxyribonucleic acid (ssDNA) for multiple detections in an early phase of screening for cervical cancer in the E6 region and became a fundamental evolution of detection electrochemical HPV biosensor. Gene profiling of the virus ssDNA sequences has been carried by high-end bioinformatics tools such as GenBank, Basic Local Alignment Searching Tools (BLAST), and Clustal OMEGA in a row. The output from bioinformatics tools resulted in 100% of similarities between our virus ssDNA probe and HPV complete genome in the databases. The cross-validation between HPV genome and our designed virus ssDNA provided high specificity and selectivity during screening methods compared with Pap smear. The DNA probe for HPV 18, 5' COOH-GAT CCA GAA GGT ACA GAC GGG GAG GGC ACG 3', while 5'COOH-GGG CGC TGT GCA GTG TGT TGG AGA CCC CGA3' as DNA probe for HPV 58 designed with 66.77% guanine (G) and cytosine (C) content for both. Our virus ssDNA probe for the HPV biosensor promises high sensitivity, specificity, selectivity, repeatability, low fluid consumption, and will be useful in mini-size diagnostic devices for cervical cancer detection.