Surface-Enhanced Raman Scattering-Based Immunoassay Technologies for Detection of Disease Biomarkers

Detection of biomarkers is of vital importance in disease detection, management, and monitoring of therapeutic efficacy. Extensive efforts have been devoted to the development of novel diagnostic methods that detect and quantify biomarkers with higher sensitivity and reliability, contributing to better disease diagnosis and prognosis. When it comes to such devastating diseases as cancer, these novel powerful methods allow for disease staging as well as detection of cancer at very early stages. Over the past decade, there have been some advances in the development of platforms for biomarker detection of diseases. The main focus has recently shifted to the development of simple and reliable diagnostic tests that are inexpensive, accurate, and can follow a patient’s disease progression and therapy response. The individualized approach in biomarker detection has been also emphasized with detection of multiple biomarkers in body fluids such as blood and urine. This review article covers the developments in Surface-Enhanced Raman Scattering (SERS) and related technologies with the primary focus on immunoassays. Limitations and advantages of the SERS-based immunoassay platform are discussed. The article thoroughly describes all components of the SERS immunoassay and highlights the superior capabilities of SERS readout strategy such as high sensitivity and simultaneous detection of a multitude of biomarkers. Finally, it introduces recently developed strategies for in vivo biomarker detection using SERS

Recent Progress in Optical Sensors for Biomedical Diagnostics

In recent years, several types of optical sensors have been probed for their aptitude in healthcare biosensing, making their applications in biomedical diagnostics a rapidly evolving subject. Optical sensors show versatility amongst different receptor types and even permit the integration of different detection mechanisms. Such conjugated sensing platforms facilitate the exploitation of their neoteric synergistic characteristics for sensor fabrication. This paper covers nearly 250 research articles since 2016 representing the emerging interest in rapid, reproducible and ultrasensitive assays in clinical analysis. Therefore, we present an elaborate review of biomedical diagnostics with the help of optical sensors working on varied principles such as surface plasmon resonance, localised surface plasmon resonance, evanescent wave fluorescence, bioluminescence and several others. These sensors are capable of investigating toxins, proteins, pathogens, disease biomarkers and whole cells in varied sensing media ranging from water to buffer to more complex environments such as serum, blood or urine. Hence, the recent trends discussed in this review hold enormous potential for the widespread use of optical sensors in early-stage disease prediction and point-of-care testing devices.DFG, 428780268, Biomimetische Rezeptoren auf NanoMIP-Basis zur Virenerkennung und -entfernung mittels integrierter Ansätz

Microfluidic Systems for Cancer Diagnostics

Cancer is the second leading cause of death in noncommunicable diseases coming right after cardiovascular diseases. Early diagnosis is a key for improving survival expectancy and treatment outcomes as cancer in early stage is more responsive to treatment. Currently, center of diseases control and prevention (CDC) recommend regular screening for cervical, breast and colorectal cancers. Although other screening procedures are available for prostate, pancreatic, thyroid and ovarian cancer, they did not prove to be effective in reducing mortality rates of these cancers. Adaption of prostate specific antigen (PSA) screening test for prostate cancer has not been related to improved survival rates instead it resulted in what has been known as “prostate cancer epidemic” due to overdiagnosis and overtreatment of prostate cancer. The dilemma of current cancer diagnostic techniques results from the trade-off between specificity and sensitivity of the cancer screening. Specific cancer screening strategies that depend on either imaging or histopathological examination are not sensitive enough and miss latent or asymptomatic cancers. While sensitive techniques that depend on biomarker screening in biofluids like PSA test are not specific enough for accurate decision. In addition, most of these techniques are time consuming, expensive and require centralized laboratories with highly trained technicians. These criteria limit the availability of cancer screening technique to developed countries with well-established healthcare systems and limit their application in areas with limited resources. The goal of this thesis is to develop and test techniques with promising specificity and sensitivity for screening and staging of different types of cancers. Several approaches have been studied to develop point-of-care (POC) sensors for prostate, head and neck cancers that are of low cost, utilizes low sample volumes, automated or semiautomated and can be utilized in remote areas with limited resources. 3D printing was used to prototype and mass produce microfluidic chips and adaptors with better fluid handling characteristics and much lower cost than traditional microfluidic systems. Panels of selected biomarker proteins were multiplexed on the same microfluidic chip to improve assay septicity while maintaining ultralow sensitivities

Analytical techniques for multiplex analysis of protein biomarkers

Introduction: The importance of biomarkers for pharmaceutical drug development and clinical diagnostics is more significant than ever in the current shift toward personalized medicine. Biomarkers have taken a central position either as companion markers to support drug development and patient selection, or as indicators aiming to detect the earliest perturbations indicative of disease, minimizing therapeutic intervention or even enabling disease reversal. Protein biomarkers are of particular interest given their central role in biochemical pathways. Hence, capabilities to analyze multiple protein biomarkers in one assay are highly interesting for biomedical research. Areas covered: We here review multiple methods that are suitable for robust, high throughput, standardized, and affordable analysis of protein biomarkers in a multiplex format. We describe innovative developments in immunoassays, the vanguard of methods in clinical laboratories, and mass spectrometry, increasingly implemented for protein biomarker analysis. Moreover, emerging techniques are discussed with potentially improved protein capture, separation, and detection that will further boost multiplex analyses. Expert commentary: The development of clinically applied multiplex protein biomarker assays is essential as multi-protein signatures provide more comprehensive information about biological systems than single biomarkers, leading to improved insights in mechanisms of disease, diagnostics, and the effect of personalized medicine

Recent advancement in sensitive detection of carcinoembryonic antigen using nanomaterials based immunosensors

Carcinoembryonic antigen (CEA) is a prominent cancer biomarker that allows for early diagnosis of various cancers. Present immunoassays techniques help quantify such target molecules in test samples via anti-antibody reaction. Despite their rapid usage, conventional immunoassay techniques demonstrate several limitations that can be easily overcome by employing nanomaterials in sensing assays. Thus, nanomaterial-based immunosensors have gained steady attention from the scientific community owing to their high specificity and low detection limit. Various nanomaterials like platinum, gold, silver and carbon exhibit exceptional properties have allowed promising results in the detection and diagnostics of CEA. Thus, the present review aims to explore the significance and the recent developments of nanomaterial-based biosensors for detecting CEA biomarkers with high sensitivity, selectivity, and specificity. After a brief introduction, we discussed the fundamentals of immunosensors immobilization strategies and common nanomaterials. In the next section, we highlighted the recent advances in the common immunosensors detection approaches for CEA alone and simultaneous detection of CEA with other biomarkers detection. Finally, we concluded the review by discussing the future perspectives of this promising field of biomarkers detection

ADVANCED IMMUNOSENSING PLATFORMS FOR BIOMONITORING AND ENVIRONMENTAL MONITORING

Chemical analysis of complex sample matrix is significant towards the efficient monitoring of human and environmental health. In the area of environmental contamination control and disease diagnosis, traditional analytical approaches rely on the separation effects by chromatography, such as gas chromatography (GC) and liquid chromatography (LC). Although GC/LC coupled with various detectors are extensively employed in analytical settings as the mature technologies, the disadvantages are also obvious, including the dependence on large and bulky instruments, complex and time-consuming instrumental operation, inevitable sample pretreatment and high cost. These disadvantages greatly limit their application in rapid diagnosis of disease, on-site samples testing, and household preclinic diagnosis. Immunosensing approaches, however, are promising substitutes applicable to the above scenarios. Featured with extraordinary selectivity and accuracy of detection attributed to the specific antibody-antigen recognition, immunoassays (IAs) have attracted extensive interests in recent years. Nevertheless, the major challenges are to overcome the inherent defects of IAs, such as low sensitivity of detection and difficult to realize multi-target simultaneous detection, in the meantime, to develop high-performance portable detection platforms. In this dissertation, advanced immunosensing platforms based on the principle of enzyme-linked immunosorbent assay (ELISA) and lateral flow immunoassay (LFIA) were systematically explored from the aspects of biorecognition, signal amplification, and signal quantification. Advanced functional nanomaterials, including metal-organic framework (MOF), graphene, carbon dot, mesoporous nanocomposite, etc., with unique physical or chemical properties were synthesized and employed as signal reporters in IAs for amplified sensitivity of detection. In addition, we designed and manufactured immunosensing platforms using 3D printing to achieve optimal integration of immunoassays, nanomaterials, and quantitative detection methods, thus the on-site, point-of-care, high-performance sample assessment was realized. Further, the extraordinary analytical performances of the immunosensing platforms were validated in practical applications for the detection of woodsmoke biomarkers in various human biofluids representing the exposure of human to contaminated air from wildfires, as well as the detection of environmental pesticide contaminants and the corresponding human metabolites in biofluids

Electrochemistry combined-surface plasmon resonance biosensors: A review

Over the years, most of the literature reported applications of electrochemical and surface plasmon resonance (SPR) immunoassays for biosensing but, so far, the combination of the two methods in the same sensing spot for analytical purposes is much less explored and discussed. The aim of this Review is to highlight the great potential of electrochemistry combined-SPR (eSPR) as analytical tool for screening chemically and biologically relevant (bio)molecules by combining the unique features of SPR integrated with electrochemical readout. In the first part of the Review, we describe the urgent need of innovative methods for screening clinical biological markers (General Introduction), briefly discuss general concepts of SPR and electrochemical sensing (Concepts behind eSPR biosensors) and highlight the hyphenation of two methods to developed combined biosensing systems (Set-up configuration and eSPR principles). Firstly, we briefly give an overview of the setup for implementation of eSPR technique and discuss some relevant experimental conditions to perform the combined optical and electrochemical measurements. Then, the principles and fundamentals of eSPR biosensors are presented and described. We also present representative examples of eSPR biosensors in the literature (Applications of eSPR biosensors). In the second part, we review studies on how combined electrical and plasmonic detection contributed to the biosensing field, in particular, for the successful screening of clinically relevant biomolecules, namely proteins (Detection of proteins), nucleic acids (Detection of nucleic acids), small size chemical species (Detection of small molecules) and cells (Living-cell Analysis). Finally, we discuss the current limitations of eSPR biosensors performance and suggest possible ways to overcome these limitations (Limitations and optimization) and then we explore aspects about the development of the method and its applications and discuss areas of likely future growth (Conclusions and perspectives).This research had the financial support of FCT (Fundação para a Ciência e Tecnologia) and co-financed by the European Union (FEDER funds) under the Partnership Agreement PT2020, Research Grant Pest-C/QUI/UIDB/00081/2020 (CIQUP). J.A. Ribeiro (ref. SFRH/BPD/105395/2014) and C.M. Pereira (ref. SFRH/BSAB/150320/2019) acknowledge FCT under the QREN – POPH – Advanced Training, subsidized by European Union and national MEC funds. The authors acknowledge the research project MyTag (ref. PTDC/EEI-EEE/4832/2021), funded by FCT, for financial support.info:eu-repo/semantics/publishedVersio