Electrochemical ELISA-based platform for bladder cancer protein biomarker detection in urine

An electrochemical aptasensor based on bimetallic carbon nanocomposites AuPt@rGO for ultrasensitive detection of adenosine on portable potentiostat

Adenosine plays a crucial role in the cardiovascular and nervous systems of living organisms. Excessive adenosine can lead to arrhythmias or heart failure, making the accurate detection of adenosine highly valuable. Given the widespread use of sensors for detecting small molecules, we propose a sensitive electrochemical aptasensor for adenosine detection in this study. The aptasensor utilized reduced graphene oxide (rGO) as the base material, and its performance was further enhanced by loading gold-platinum nanoparticles (AuPt@rGO) to improve the current response. The AuPt@rGO composite was synthesized using a simple process and was modified onto screen-printed electrodes (SPE) fabricated in the laboratory. This modification increased the effective area of the working electrode, providing more contact sites and enhancing sensitivity for adenosine detection. As a result, the sensor exhibited excellent performance in selectivity, sensitivity, and stability, with a linear response range for adenosine from 10 nM to 10 μM and a detection limit of 1.28 nM (n = 3). Furthermore, successful detection of adenosine levels in real samples was achieved using a portable potentiostat, demonstrating excellent recovery rates (95.99 %-103.4 %). These results indicate the aptasensor's significant potential for future applications in field analysis and medical diagnostics.

Leveraging microfluidic confinement to boost assay sensitivity and selectivity

The native and tunable microscale fluid manipulation accessible within 3D-printed configurations can be a transformative tool in biosensing, promoting mass transport and sample mixing to boost assay performance. In this study, we demonstrate that channel height restrictions can support a 2000% acceleration in target recruitment kinetics, a notable 600% improvement in target response magnitude, and a 300% enhancement in assay selectivity within an entirely reagentless format that requires neither catalytic amplification nor the employment of specialized nanomaterials. This highly accessible experimental configuration supports robust target detection from serum at simple, untreated, and un-passivated sensor surfaces. The underlying operational principles have been elucidated through a combination of theoretical analysis and COMSOL simulation; the enhanced analyte flux leveraged by channel confinement is directly responsible for these effects, which also scale with both bioreceptor surface density and target binding affinity. The operational simplicity of this assay format with its resolved channel and flux promoted assay performance, holds significant value not only for biosensing but also for broader microfluidic-integrated applications, such as biosynthesis and catalysis.

Evaluation of Chlorella vulgaris as sensitive, cost-effective, and environmentally sustainable biosensor tools for heavy metal monitoring in aquatic ecosystems

This study evaluates the effectiveness of single-cell microalgae as sensitive, cost-effective, and environmentally sustainable biosensors for detecting heavy metal contamination in aquatic ecosystems. A preliminary investigation compared the sensitivity of Nostoc commune and Chlorella vulgaris to chromium (Cr), cadmium (Cd), and mercury (Hg). C. vulgaris exhibited greater sensitivity, with Kautsky fluorescence increases of 67.82% (Cr VI, 200 µmol), 67.1% (Cd II, 100 µmol), and 35.27% (Hg, 1 µmol), whereas N. commune showed 124.70% (Cr VI, 200 µmol), 118.04% (Cd II, 200 µmol), and 61.96% (Hg, 1 µmol). Given its higher sensitivity, C. vulgaris was selected for biosensor development. The biosensor was optimized for pH (5-9), metal concentrations (Cr⁶⁺ and Cd2⁺ at 1-100 µmol, Hg2⁺ at 1-20 µmol), and algal density, while also evaluating immobilization effects on storage stability and sensitivity. Results showed a time-dependent increase in fluorescence with rising metal concentrations, demonstrating the biosensor's efficacy in detecting heavy metals. The calculated LC50 values were 67.32 µmol (Cd2⁺), 79.2 µmol (Cr⁶⁺), and 7.2 µmol (Hg2⁺), indicating the highest sensitivity to mercury. Immobilization enhanced biosensor stability, but sensitivity declined over extended storage, particularly at higher metal concentrations. Naked eye assessments confirmed superior sensitivity to mercury, reinforcing C. vulgaris as a promising biosensor for trace metal detection.

Trends in ready-to-use portable electrochemical sensing devices for healthcare diagnosis

Compared with previous decades, healthcare has emerged as a key global concern in light of the recurrent outbreak of pandemics. The initial stage in the provision of healthcare involves the process of diagnosis. Countries worldwide advocate for healthcare research due to its efficacy and capacity to assist diverse populations. Enhanced levels of healthcare management can be attained by the implementation of rapid diagnostic procedures and cognitive data analysis. Therefore, there is a constant need for smart therapeutics, analytical tools, and diagnostic systems to improve health and well-being. The past decade witnessed enormous growth in the sensing detection systems integrated into smartphones with printed electrodes and wearable patches for the screening of various healthcare diagnostics biomarkers and therapeutic drugs. This review focuses on the expansion of point-of-care technologies and their incorporation into a broader array of portable devices, a critical aspect in the context of decentralized societies and their healthcare systems. Discussions are broadly focused on the different sensing platforms such as solid electrodes, screen-printed electrodes, and paper-based sensing strategies for the detection of various biomarkers and therapeutic drugs. We also discuss the next-generation healthcare wearable sensing device importance and future research possibilities. Finally, the portable electrochemical sensing devices and their future perspective developments towards healthcare diagnosis are critically summarized.

New Challenges in Bladder Cancer Diagnosis: How Biosensing Tools Can Lead to Population Screening Opportunities

Bladder cancer is one of the most common cancers worldwide. Despite its high incidence, cystoscopy remains the currently used diagnostic gold standard, although it is invasive, expensive and has low sensitivity. As a result, the cancer diagnosis is mostly late, as it occurs following the presence of hematuria in urine, and population screening is not allowed. It would therefore be desirable to be able to act promptly in the early stage of the disease with the aid of biosensing. The use of devices/tools based on genetic assessments would be of great help in this field. However, the genetic differences between populations do not allow accurate analysis in the context of population screening. Current research is directed towards the discovery of universal biomarkers present in urine with the aim of providing an approach based on a non-invasive, easy-to-perform, rapid, and accurate test that can be widely used in clinical practice for the early diagnosis and follow-up of bladder cancer. An efficient biosensing device may have a disruptive impact in terms of patient health and disease management, contributing to a decrease in mortality rate, as well as easing the social and economic burden on the national healthcare system. Considering the advantage of accessing population screening for early diagnosis of cancer, the main challenges and future perspectives are critically discussed to address the research towards the selection of suitable biomarkers for the development of a very sensitive biosensor for bladder cancer.

Diagnosis of early-stage bladder cancer via unprocessed urine samples at the point of care

Diagnostic kits for the optical detection of bladder cancer in urine can facilitate effective screening and surveillance. However, the heterogeneity of urine samples, owing to patients with bladder cancer often presenting with haematuria, interfere with the transduction of the optical signal. Here we describe the development and point-of-care performance of a device for the detection of bladder cancer that obviates the need for sample processing. The device leverages the enzymatic release of organogel particles carrying solvatochromic fluorophores in the presence of urinary hyaluronidases-a bladder cancer biomarker. Owing to buoyancy, the particles transfer from the urine sample into the organic phase, where the change in fluorescence can be measured via a smartphone without interference from blood proteins. In a double-blind study with 80 unprocessed urine samples from patients with bladder cancer (including samples with haematuria) or other genitourinary diseases and with 25 samples from healthy participants, our system distinguished the cancerous samples, including those with early-stage bladder cancer, with accuracies of about 90%. Obviating the need for sample pretreatment may facilitate the at-home detection of bladder cancer.

An electrochemical ratiometric immunosensor for the detection of NMP22 based on ZIF-8@MWCNTs@Chit@Fc@AuNPs and AuPt-MB

Nuclear matrix protein 22 (NMP22) is one of the most important tumor markers of bladder cancer and is significantly elevated in the urine of bladder cancer patients. Therefore, in this work, a highly sensitive ratiometric electrochemical immunosensor was constructed to detect NMP22 based on ZIF-8@MWCNTs@Chit@Fc@AuNPs composites. ZIF-8 had a large surface area and good adsorption ability. Multi-Walled Carbon Nanotubes (MWCNTs) can optimize the electrical conductivity of ZIF-8, so that the electrode surface of ferrocene (Fc) obtains a stable and strong electrochemical signal. In addition, AuPt-MB provided another strong detection signal methylene blue (MB) while immobilizing the secondary antibody (Ab2) through Au-N and Pt-N bonds. A ratiometric electrochemical sensor was formed based on ZIF-8@MWCNTs@Chit@Fc@AuNPs and AuPt-MB, which showed a great linear connection between IMB/IFc and the logarithmic concentration of NMP22 with a detection limit of 3.33 fg mL-1 (S/N = 3) under optimized specifications in the concentration interval of 0.01 pg mL-1 to 1000 ng mL-1. In addition, the ratiometric immunosensor showed good selectivity and stability.

Organic Electrochemical Transistors for Biomarker Detections

The improvement of living standards and the advancement of medical technology have led to an increased focus on health among individuals. Detections of biomarkers are feasible approaches to obtaining information about health status, disease progression, and response to treatment of an individual. In recent years, organic electrochemical transistors (OECTs) have demonstrated high electrical performances and effectiveness in detecting various types of biomarkers. This review provides an overview of the working principles of OECTs and their performance in detecting multiple types of biomarkers, with a focus on the recent advances and representative applications of OECTs in wearable and implantable biomarker detections, and provides a perspective for the future development of OECT-based biomarker sensors.

CFHR1 involvement in bile duct carcinoma: Insights from a data mining study

The aim of this study is to investigate the role of CFHR1 in bile duct carcinoma (BDC) and its mechanism of action, and we hope that our analysis and research will contribute to a better understanding of cholangiocarcinoma (BDC) disease genesis, progression and the development of new therapeutic strategies. The prognostic receiver operating characteristic curve of CFHR1 was generated using survival ROC. The ROC curve for CFHR1 showed that there is a correlation between CFHR1 expression and clinicopathological parameters and has an impact on poor prognosis. STRING was used to predict the protein-protein interaction network of the identified genes, and the Microenvironment Cell Populations counter algorithm was used to analyze immune cell infiltration within the BDC. The combined analysis showed that CFHR1 was found to be upregulated in BDC tissues, along with a total of 20 related differentially expressed genes (DEGs) (8 downregulated and 12 upregulated genes). Also, the results showed that the expression of CFHR1 is correlated with immune cell infiltration in tumor and immune cell markers in BDC (P < 0.05). In addition, we have verified experimentally the biological function of CFHR1. These findings suggest that CFHR1 may be a prognostic marker and a potential therapeutic target for BDC. Information regarding the detailed roles of CFHR1 in BDC could be valuable for improving the diagnosis and treatment of this rare cancer.

Potential-resolved electrochemiluminescence for simultaneous determination of multiplex bladder cancer markers

A novel ECL immunosensor was developed for simultaneous determination of multiplex bladder cancer markers. DNA tetrahedra act as capture probes, while Ru-MOF@AuNPs and AuAgNCs act as signal reporters, yielding well-separated signals reflecting NUMA1 and CFHR1 concentrations. This strategy offers a new platform for clinical immunoassays, enabling simultaneous multiplex tumor marker detection.

Biomarkers for Early Cancer Detection: A Landscape View of Recent Advancements, Spotlighting Pancreatic and Liver Cancers

Cancer is one of the leading causes of death worldwide. Early cancer detection is critical because it can significantly improve treatment outcomes, thus saving lives, reducing suffering, and lessening psychological and economic burdens. Cancer biomarkers provide varied information about cancer, from early detection of malignancy to decisions on treatment and subsequent monitoring. A large variety of molecular, histologic, radiographic, or physiological entities or features are among the common types of cancer biomarkers. Sizeable recent methodological progress and insights have promoted significant developments in the field of early cancer detection biomarkers. Here we provide an overview of recent advances in the knowledge related to biomolecules and cellular entities used for early cancer detection. We examine data from the CAS Content Collection, the largest human-curated collection of published scientific information, as well as from the biomarker datasets at Excelra, and analyze the publication landscape of recent research. We also discuss the evolution of key concepts and cancer biomarkers development pipelines, with a particular focus on pancreatic and liver cancers, which are known to be remarkably difficult to detect early and to have particularly high morbidity and mortality. The objective of the paper is to provide a broad overview of the evolving landscape of current knowledge on cancer biomarkers and to outline challenges and evaluate growth opportunities, in order to further efforts in solving the problems that remain. The merit of this review stems from the extensive, wide-ranging coverage of the most up-to-date scientific information, allowing unique, unmatched breadth of landscape analysis and in-depth insights.

Plasmonic Fluorescence Sensors in Diagnosis of Infectious Diseases

The increasing demand for rapid, cost-effective, and reliable diagnostic tools in personalized and point-of-care medicine is driving scientists to enhance existing technology platforms and develop new methods for detecting and measuring clinically significant biomarkers. Humanity is confronted with growing risks from emerging and recurring infectious diseases, including the influenza virus, dengue virus (DENV), human immunodeficiency virus (HIV), Ebola virus, tuberculosis, cholera, and, most notably, SARS coronavirus-2 (SARS-CoV-2; COVID-19), among others. Timely diagnosis of infections and effective disease control have always been of paramount importance. Plasmonic-based biosensing holds the potential to address the threat posed by infectious diseases by enabling prompt disease monitoring. In recent years, numerous plasmonic platforms have risen to the challenge of offering on-site strategies to complement traditional diagnostic methods like polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays (ELISA). Disease detection can be accomplished through the utilization of diverse plasmonic phenomena, such as propagating surface plasmon resonance (SPR), localized SPR (LSPR), surface-enhanced Raman scattering (SERS), surface-enhanced fluorescence (SEF), surface-enhanced infrared absorption spectroscopy, and plasmonic fluorescence sensors. This review focuses on diagnostic methods employing plasmonic fluorescence sensors, highlighting their pivotal role in swift disease detection with remarkable sensitivity. It underscores the necessity for continued research to expand the scope and capabilities of plasmonic fluorescence sensors in the field of diagnostics.

Ultrasensitive Electrochemiluminescence Immunosensor for Bladder Marker Human Complement Factor H-Related Protein Detection

The development of noninvasive and sensitive detection methods for the early diagnosis and monitoring of bladder cancer is critical but challenging. Herein, an ultrasensitive electrochemiluminescence (ECL) immunosensor that uses Ru(bpy)₃²⁺-metal-organic framework (Ru-MOF) nanospheres and a DNA tetrahedral (TDN) probe was established for bladder cancer marker complement factor H-related protein (CFHR1) detection. The synthesized Ru(bpy)₃²⁺-metal-organic frameworks (Ru-MOFs) served as a linked substrate for immobilization of AuNPs and antibody (Ab₂) to prepare the ECL signal probe (Ru-MOF@AuNPs-Ab₂), exhibiting a stable and strengthened ECL emission. At the same time, the inherent advantages of TDN probes on the electrode as the capture probe (TDN-Ab₁) improve the accessibility of targets to probes. In the presence of CFHR1, the signal probe Ru-MOF@AuNPs-Ab₂ was modified on the electrode through immune binding, thereby obtaining an outstanding ECL signal. As expected, the developed ECL immunosensor exhibited splendid performance for CFHR1 detection in the range of 0.1 fg/mL to 10 pg/mL with a quite low detection limit of 0.069 fg/mL. By using the proposed strategy to detect CFHR1 from urine, it showed acceptable accuracy, which can effectively distinguish between bladder cancer patients and healthy samples. This work contributes to a novel, noninvasive, and accurate method for early clinical diagnosis of bladder cancer.

Designing Intelligent Nanomaterials to Achieve Highly Sensitive Diagnoses and Multimodality Therapy of Bladder Cancer

Bladder cancer (BC) is among the most common malignant tumors of the genitourinary system worldwide. In recent years, the rate of BC incidence has increased, and the recurrence rate is high, resulting in poor quality of life for patients. Therefore, how to develop an effective method to achieve synchronous precise diagnoses and BC therapies is a difficult problem to solve clinically. Previous reports usually focus on the role of nanomaterials as drug delivery carriers, while a summary of the functional design and application of nanomaterials is lacking. Summarizing the application of functional nanomaterials in high-sensitivity diagnosis and multimodality therapy of BC is urgently needed. This review summarizes the application of nanotechnology in BC diagnosis, including the application of nanotechnology in the sensoring of BC biomarkers and their role in monitoring BC. In addition, conventional and combination therapies strategy in potential BC therapy are analyzed. Moreover, different kinds of nanomaterials in BC multimodal therapy according to pathological features of BC are also outlined. The goal of this review is to present an overview of the application of nanomaterials in the theranostics of BC to provide guidance for the application of functional nanomaterials to precisely diagnose and treat BC.

Recent Progress in Nanomaterial-Based Biosensors and Theranostic Nanomedicine for Bladder Cancer

Bladder cancer (BCa) is one of the most expensive and common malignancies in the urinary system due to its high progression and recurrence rate. Although there are various methods, including cystoscopy, biopsy, and cytology, that have become the standard diagnosis methods for BCa, their intrinsic invasive and inaccurate properties need to be overcome. The novel urine cancer biomarkers are assisted by nanomaterials-based biosensors, such as field-effect transistors (FETs) with high sensitivity and specificity, which may provide solutions to these problems. In addition, nanomaterials can be applied for the advancement of next-generation optical imaging techniques and the contrast agents of conventional techniques; for example, magnetic resonance imaging (MRI) for the diagnosis of BCa. Regarding BCa therapy, nanocarriers, including mucoadhesive nanoparticles and other polymeric nanoparticles, successfully overcome the disadvantages of conventional intravesical instillation and improve the efficacy and safety of intravesical chemotherapy for BCa. Aside from chemotherapy, nanomedicine-based novel therapies, including photodynamic therapy (PDT), photothermal therapy (PTT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), and combination therapy, have afforded us new ways to provide BC therapy and hope, which can be translated into the clinic. In addition, nanomotors and the nanomaterials-based solid tumor disassociation strategy provide new ideas for future research. Here, the advances in BCa diagnosis and therapy mentioned above are reviewed in this paper.

Cancer-Associated Membrane Protein as Targeted Therapy for Bladder Cancer

Bladder cancer (BC) recurrence is one of the primary clinical problems encountered by patients following chemotherapy. However, the mechanisms underlying their resistance to chemotherapy remain unclear. Alteration in the pattern of membrane proteins (MPs) is thought to be associated with this recurrence outcome, often leading to cell dysfunction. Since MPs are found throughout the cell membrane, they have become the focus of attention for cancer diagnosis and treatment. Identifying specific and sensitive biomarkers for BC, therefore, requires a major collaborative effort. This review describes studies on membrane proteins as potential biomarkers to facilitate personalised medicine. It aims to introduce and discuss the types and significant functions of membrane proteins as potential biomarkers for future medicine. Other types of biomarkers such as DNA-, RNA- or metabolite-based biomarkers are not included in this review, but the focus is mainly on cell membrane surface protein-based biomarkers.

Role of Paper-Based Sensors in Fight against Cancer for the Developing World

Cancer is one of the major killers across the globe. According to the WHO, more than 10 million people succumbed to cancer in the year 2020 alone. The early detection of cancer is key to reducing the mortality rate. In low- and medium-income countries, the screening facilities are limited due to a scarcity of resources and equipment. Paper-based microfluidics provide a platform for a low-cost, biodegradable micro-total analysis system (µTAS) that can be used for the detection of critical biomarkers for cancer screening. This work aims to review and provide a perspective on various available paper-based methods for cancer screening. The work includes an overview of paper-based sensors, the analytes that can be detected and the detection, and readout methods used.

Poly(amidoamine) dendrimer immunosensor for ultrasensitive gravimetric and electrochemical detection of matrix metalloproteinase-9

Monitoring the level of matrix metalloproteinase-9 (MMP-9) and inhibiting its expression is important for the diagnosis and treatment of various diseases. However, the analysis of MMP-9 is challenging owing to its very low content in the blood, especially at the early stages of diseases. Therefore, we developed an ultrasensitive and easy-to-use immunosensor based on a three-dimensional (3D) bioplatform for the determination of the total MMP-9 concentration in plasma. The used 3D bioplatform (G2 poly(amidoamine) dendrimer; PAMAM) improved the sensitivity of the determination by significantly expanding the surface area of the receptor layer. The antigen-antibody recognition process was controlled by quartz crystal microbalance with dissipation (QCM-D) and electrochemical impedance spectroscopy (EIS). The effect of the orientation of antibody molecules in the sensing layer on the work parameters of the immunosensor was analyzed using unmodified PAMAM (PAMAM-NH₂) and PAMAM functionalized with -COOH groups (PAMAM-COOH). The developed immunosensor based on PAMAM-NH₂ was characterized by a lower detection limit (LOD = 2.0 pg⋅mL^-1) and wider analytical range (1·10^-4 - 5 μg⋅mL^-1 for EIS and QCM-D) compared to PAMAM-COOH immunosensor (EIS: 1·10^-4 - 0.5 μg⋅mL^-1; QCM-D: 5·10^-4 - 0.5 μg⋅mL^-1). The functionality of the proposed device was verified in spiked plasma. The recoveries determined in commercial human and rat plasma and noncommercial rat plasma were very close to the value of 100% and in the range of 96-120% for Au/PAMAM-NH₂/Ab and Au/PAMAM-COOH/Ab immunosensors, respectively. The designed analytical devices showed high selectivity and sensitivity without the use of any amplifiers such as metal nanoparticles or enzymes.

Electrochemical Biosensor Employing Bi2S3 Nanocrystals-Modified Electrode for Bladder Cancer Biomarker Detection

Bladder cancer is a kind of malignant tumor with high incidence in the urinary system, complex pathogenic causes, and the high recurrence rate. Biosensors capable of rapid, on site, and accurate bladder cancer diagnosis method continue to be lacking. Here, the electrochemical biosensor for detecting cytokeratin 18 (CK18, bladder cancer biomarker) was constructed based on the chemically modified electrode (CME). The work electrode (WE) was modified by bismuth sulfide semiconductor nanocrystals (Bi2S3 NCs), and then immobilized with CK18 antibodies and blocking agents to complete the electrode preparation. The results indicated that the interface of a flexible carbon electrode with Bi2S3 NCs film was steady with reliable charge transfer capability. With the large specific area and quantum size effect, the proposed sensor could detect CK18 antigen protein with an ultralow detection limit of 1.87 fM (fmol L−1) and wide linear dynamic range of 1–1000 pg mL−1, respectively. Detecting results could be read in less than 30 s with the portable, planar flexible CME. The sensitive and specific electrochemical biosensor possessed the characteristics of rapidity, ease-of-use, and non-invasive detection, indicating the application prospect in the early screening of bladder cancer and other diseases.

A Systematic Study and Potential Limitations of Proton-ELISA Platform for α-Synuclein Antigen Detection

To evaluate point-of-care testing (POCT) for the potential early detection of biomarkers of Parkinson’s disease, a systematic investigation of portable and low-cost platforms is performed based on the Proton-enzyme-linked immunosorbent assay (Proton-ELISA) methodology. The detection of the α-synuclein antigen was first presented by biotin-relative linkers, and glucose substrate solution was first performed with a systematic experimental design to optimize the sensing results. All materials in this study are commercially available. Three different experiments with the partitional check were performed to investigate the Proton-ELISA platform, including proton catalyzed efficiency, blocking efficiency, and full Proton-ELISA procedure. The response time was selected as 15 min by the time-dependent curves of a full reaction. The limit of detection of conventional ELISA kits is 0.169 ng/mL, which is much lower than the Proton-ELISA results. The final response of the full Proton-ELISA procedure to pH changes was approximately 0.60 and 0.12 for α-synuclein antigen concentrations of 100 ng/mL and 4 ng/mL, respectively. With the partitional check, pH changes of pure glucose substrate and conjugated oxidase and interference of the nonspecific binding are 1.7 and 0.04, respectively. The lower pH changes far from the partitional check results can be concluded for the properties of glucose oxidase conjugation, including the isoelectric point and binding affinity modification by the testing environment. This preliminary guideline can be used as a lesson learnt to speed up following studies of the evaluation and optimization of other antigen detection. Therefore, Proton-ELISA can be suggested for some special applications with the help of custom-designed conjugation in the environment with less degradation or interference and a proper detection concentration range.

The Clinical Significance and Prognostic Value of HER2 Expression in Bladder Cancer: A Meta-Analysis and a Bioinformatic Analysis

OBJECTIVE

Human Epidermal Growth Factor Receptor 2 (HER2) is highly expressed in multiple malignancies and associated with patients' prognosis, but its role in bladder cancer (BCa) remains elusive. We conducted this meta-analysis to explore the clinical significance and prognostic value of HER2 in BCa.

METHODS

PubMed was searched for studies published between January 1, 2000 and January 1, 2020. The odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (95%CIs) were used to investigate the relationship between HER2 and BCa pathological features. TCGA was mined for the information regarding as well.

RESULTS

Our study included 14 articles enrolling 1398 people. Expression of HER2 is higher in bladder cancer than in normal tissues. HER2 over-expression is associated with CIS, multifocal tumor, large tumor size, high tumor stage and grade, lymph node metastasis, progression, recurrence and papillary tumor. We could not find a significant association between HER2 expression and survival time in BCa patients.

CONCLUSIONS

Our meta and bioinformatic analysis indicated that HER2 expression was related to pathological malignancy and poor prognosis in BCa.

A fast and ultrasensitive ELISA based on rolling circle amplification

A highly sensitive ELISA is critical for early diagnosis and biomarker discovery of various diseases. Although various ELISA technologies have been developed with high sensitivity, they are limited by poor repeatability, high cost, the dependence on complex equipment and/or a prolonged reaction time. To this end, we developed a fast and ultrasensitive ELISA (termed RELISA) based on rolling circle amplification (RCA) and enzymatic signal amplification. The RELISA is established on the traditional ELISA, with only one more RCA step that can be accomplished within 10 minutes. The prolonged single strand DNA (ssDNA) from RCA is able to enrich abundant horseradish peroxidase conjugate (HRP) modified detection probes. Consequently, the intensive HRP is able to catalyze TMB-H₂O₂ to produce significantly enhanced colorimetric signals. With CEACAM-7 as a model biomarker, the RELISA achieves the limit of detection as low as 2.82 pg mL^-1, which is ∼50 times higher than that of the traditional ELISA. Therefore, we envision that the developed RELISA would be a powerful tool for the early diagnosis of various major diseases.

Review: Detection and quantification of proteins in human urine

Extensive medical research showed that patients, with high protein concentration in urine, have various kinds of kidney diseases, referred to as proteinuria. Urinary protein biomarkers are useful for diagnosis of many health conditions - kidney and cardio vascular diseases, cancers, diabetes, infections. This review focuses on the instrumental quantification (electrophoresis, chromatography, immunoassays, mass spectrometry, fluorescence spectroscopy, the infrared spectroscopy, and Raman spectroscopy) of proteins (the most of all albumin) in human urine matrix. Different techniques provide unique information on what constituents of the urine are. Due to complex nature of urine, a separation step by electrophoresis or chromatography are often used for proteomics study of urine. Mass spectrometry is a powerful tool for the discovery and the analysis of biomarkers in urine, however, costs of the analysis are high, especially for quantitative analysis. Immunoassays, which often come with fluorescence detection, are major qualitative and quantitative tools in clinical analysis. While Infrared and Raman spectroscopies do not give extensive information about urine, they could become important tools for the routine clinical diagnostics of kidney problems, due to rapidness and low-cost. Thus, it is important to review all the applicable techniques and methods related to urine analysis. In this review, a brief overview of each technique's principle is introduced. Where applicable, research papers about protein determination in urine are summarized with the main figures of merits, such as the limit of detection, the detectable range, recovery and accuracy, when available.

Streaming-enhanced, chip-based biosensor with acoustically active, biomarker-functionalized micropillars: A case study of thrombin detection

Enzyme-linked immunosorbent assay is a widely used analytical technique for detecting and quantifying disease-specific protein biomarkers. Despite recent progresses in disease-specific protein biomarkers detection with microfluidic chips, many devices still suffer from the limited mass transport of target molecules, and consequently low detection efficiency or long incubation time. In this work, we present a novel strategy to significantly enhance the sensing efficiency of a chip-based biosensor by exploiting micro-streaming in an acoustofluidic device, which boosts intermolecular interactions and a hybridization chain reaction to increase the fluorescent signals. This device was made of a microfluidic chip that contains an array of PDMS micropillars in a ship-shaped microchannel. And the inner surface of the channel was functionalized with capture aptamers that bind with thrombin, chosen as a model target molecule. An ultrasonic transducer underneath the chip operating at 150 kHz generates circular micro-streaming flows around the pillars that significantly improves the binding efficiency of thrombin with capture aptamers by 1) increasing the retention time and 2) enhancing mass transport via local convection versus diffusion. The effects of ultrasound parameters, such as operating frequencies and voltages, on the distribution and magnitude of flows were optimized to obtain a better performance of the sensor chip. Under the optimized conditions, the detection limit was increased by one order of magnitude. Although this work has focused on the detection of thrombin as a model molecule, this streaming-enhanced, microstructure-based sensing strategy can be applied to detect a wide range of molecules or even cells.

Novel circulating protein biomarkers for thyroid cancer determined through data-independent acquisition mass spectrometry

Background

Distinguishing between different types of thyroid cancers (TC) remains challenging in clinical laboratories. As different tumor types require different clinical interventions, it is necessary to establish new methods for accurate diagnosis of TC.

Methods

Proteomic analysis of the human serum was performed through data-independent acquisition mass spectrometry for 29 patients with TC (stages I–IV): 13 cases of papillary TC (PTC), 10 cases of medullary TC (MTC), and six cases follicular TC (FTC). In addition, 15 patients with benign thyroid nodules (TNs) and 10 healthy controls (HCs) were included in this study. Subsequently, 17 differentially expressed proteins were identified in 291 patients with TC, including 247 with PTC, 38 with MTC, and six with FTC, and 69 patients with benign TNs and 176 with HC, using enzyme-linked immunosorbent assays.

Results

In total, 517 proteins were detected in the serum samples using an Orbitrap Q-Exactive-plus mass spectrometer. The amyloid beta A4 protein, apolipoprotein A-IV, gelsolin, contactin-1, gamma-glutamyl hydrolase, and complement factor H-related protein 1 (CFHR1) were selected for further analysis. The median serum CFHR1 levels were significantly higher in the MTC and FTC groups than in the PTC and control groups (P < 0.001). CFHR1 exhibited higher diagnostic performance in distinguishing patients with MTC from those with PTC (P < 0.001), with a sensitivity of 100.0%, specificity of 85.08%, area under the curve of 0.93, and detection cut-off of 0.92 ng/mL.

Conclusion

CFHR1 may serve as a novel biomarker to distinguish PTC from MTC with high sensitivity and specificity.

Multisensor Systems and Arrays for Medical Applications Employing Naturally-Occurring Compounds and Materials

The significant improvement of quality of life achieved over the last decades has stimulated the development of new approaches in medicine to take into account the personal needs of each patient. Precision medicine, providing healthcare customization, opens new horizons in the diagnosis, treatment and prevention of numerous diseases. As a consequence, there is a growing demand for novel analytical devices and methods capable of addressing the challenges of precision medicine. For example, various types of sensors or their arrays are highly suitable for simultaneous monitoring of multiple analytes in complex biological media in order to obtain more information about the health status of a patient or to follow the treatment process. Besides, the development of sustainable sensors based on natural chemicals allows reducing their environmental impact. This review is concerned with the application of such analytical platforms in various areas of medicine: analysis of body fluids, wearable sensors, drug manufacturing and screening. The importance and role of naturally-occurring compounds in the development of electrochemical multisensor systems and arrays are discussed.

Biomarkers detection with magnetoresistance-based sensors

Biosensing platforms for detecting and quantifying biomarkers have played an important role in the past decade. Among them, platforms based on magnetoresistance (MR) sensing technology are attractive. The resistance value of the material changes with the externally applied magnetic field is the core mechanism of MR sensing technology. A typical MR-based sensor has the characteristics of cost-effective, simple operation, high compactness, and high sensitivity. Moreover, using magnetic nanoparticles (MNPs) as labels, MR-based sensors have the ability to overcome the high background noise of complex samples, so they are particularly suitable for point-of-care testing (POCT). However, the problem still exists. How to obtain high-throughput, that is, multiple detections of biomarkers in MR-based sensors, thereby improving detection efficiency and reducing the burden on patients is an important issue in future work. This paper reviews three MR-based detection technologies for the detection of biomarkers, i.e., anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), and tunneling magnetoresistance (TMR). Based on these three common technologies, different typical applications that include biomedical diagnosis, food safety, and environmental monitoring are presented. Furthermore, the existing MR-based detection method is better expanded to make it more in line with present detection needs by combining different advanced technologies including microfluidics, Microelectromechanical systems (MEMS), and Immunochromatographic test strips (ICTS). And then, a brief discussion of current challenges and perspectives of MR-based sensors are pointed out.

Bladder cancer hunting: A microfluidic paper-based analytical device

Bladder cancer is the fourth most common cancer in men, and it is becoming a prevalent malignancy. Most of the regular clinical examinations are prompt evaluations with cystoscopy, renal function testing, which require high-precision instrument, well-trained operators, and high cost. In this study, a microfluidic paper-based analytical device (μPAD) was fabricated to detect nuclear matrix protein 22 (NMP22) and bladder cancer antigen (BTA) from the urine samples. Urine samples were collected from 11 bladder cancer patients and 10 well-beings as experiment and control groups, respectively, to verify the working efficiency of μPAD. A remarkable checkout efficiency of up to 90.91% was found from the results. Meanwhile, this method is feasible for home-based self-detection from urine samples within 10 min for the total process, which provides a new way for quick, economical, and convenient tumor diagnosis, prognosis evaluation, and drug response.

Integrated Single Microbead-Arrayed μ-Fluidic Platform for the Automated Detection of Multiplexed Biomarkers

An automated, single microbead-arrayed μ-fluidic immunoassay (AMIA) device is innovatively devised in this study, which enables the highly sensitive and simultaneous detection of multiplex biomarkers with fully automatic operations. The AMIA platform not only achieves automated assay processing and multiplexed target detection by integrating single microbead manipulation, sample loading, multistep washing, and immunoreaction on a microfluidic chip but also confers high sensitivity due to the highly efficient signal enriching effect on a single microbead by the use of only a routine sandwich immunoreaction. As such, as low as the pg/mL level of multiplexed protein biomarkers can be simultaneously determined in a quite small volume of serum (∼20 μL is enough), which can well meet the clinical demand for disease screening and prognosis. What is more, the detection results of several clinically important biomarkers in clinical samples with the AMIA platform exhibit excellent consistency with those obtained by using a standard clinical test. Thus, in virtue of the excellent features in terms of high sensitivity, multiplexing capability, generality, and high degree of automation, the AMIA provides a practical and user-friendly platform for assaying different biomarkers in clinical diagnostics and point-of-care testing.

Ultrasensitive melanoma biomarker detection using a microchip SERS immunoassay with anisotropic Au–Ag alloy nanoboxes

The detection of circulating biomarkers in liquid biopsies has the potential to provide a non-invasive route for earlier cancer diagnosis and treatment management. Melanoma chondroitin sulfate proteoglycan (MCSP) is a membrane protein characteristic for melanoma cell migration and tissue invasion with its soluble form (sMCSP) serving as a potential promising diagnostic surrogate. However, at the initial disease stage, the detection of sMCSP is challenging because of its low abundance and the required high specificity to analyze sMCSP in complex bodily fluids. Herein, we report a highly sensitive and high-throughput microchip that enables Surface Enhanced Raman Spectroscopy (SERS) immunoassay for parallel detection of up to 28 samples. Key to assay speed and sensitivity is the stimulation of an alternating current-induced nanofluidic mixing that improves target-sensor collision and displacement of non-specific molecules. Anisotropic Au–Ag alloy nanoboxes (NB's) with strong plasmonic hot spots provide single SERS particle sensitivity that enables ultrasensitive sMCSP detection of as low as 0.79 pM (200 pg ml⁻¹). As a proof of concept study, we investigate the assay performance in simulated melanoma patient samples.

The detection of circulating biomarkers in liquid biopsies has the potential to provide a non-invasive route for earlier cancer diagnosis and treatment management.

Recent Progress of Biomarker Detection Sensors

Early cancer diagnosis and treatment are crucial research fields of human health. One method that has proven efficient is biomarker detection which can provide real-time and accurate biological information for early diagnosis. This review presents several biomarker sensors based on electrochemistry, surface plasmon resonance (SPR), nanowires, other nanostructures, and, most recently, metamaterials which have also shown their mechanisms and prospects in application in recent years. Compared with previous reviews, electrochemistry-based biomarker sensors have been classified into three strategies according to their optimizing methods in this review. This makes it more convenient for researchers to find a specific fabrication method to improve the performance of their sensors. Besides that, as microfabrication technologies have improved and novel materials are explored, some novel biomarker sensors-such as nanowire-based and metamaterial-based biomarker sensors-have also been investigated and summarized in this review, which can exhibit ultrahigh resolution, sensitivity, and limit of detection (LoD) in a more complex detection environment. The purpose of this review is to understand the present by reviewing the past. Researchers can break through bottlenecks of existing biomarker sensors by reviewing previous works and finally meet the various complex detection needs for the early diagnosis of human cancer.

CFHR1 is a potentially downregulated gene in lung adenocarcinoma

There is increasing evidence that human complement factor H‑related protein 1 (CFHR1) plays a crucial role in the development of malignant diseases. However, few studies have identified the roles of CFHR1 in the occurrence and prognosis of lung adenocarcinoma (LADC). In the present study, comprehensive bioinformatic analyses of data obtained from the Oncomine platform, UALCAN and Gene Expression Profiling Interactive Analysis (GEPIA) demonstrated that CFHR1 expression is significantly reduced in both LADC tissues and cancer cells. The patients presenting with downregulation of CFHR1 had significantly lower overall survival (OS) and post progression survival (PPS) times. Through analysis of the datasets from Gene Expression Omnibus database, we found that the compound actinomycin D promoted CFHR1 expression, further displaying the cytotoxic effect in the LADC cell line A549. In addition, the expression level of CFHR1 in the cisplatin‑resistant LADC cell line CDDP‑R (derived from H460) was also significantly reduced. Our research demonstrated that low levels of CFHR1 are specifically found in LADC samples, and CFHR1 could serve as a potential therapeutic target for this subset of lung cancers. Determination of the detailed roles of CFHR1 in LADC biology could provide insightful information for further investigations.

Quantitative analysis of liquid crystal-based immunoassay using rectangular capillaries as sensing platform

In past studies, liquid crystal (LC)-based immunoassays were accomplished by fabricating an LC cell with two pieces of glass slides after immunobinding, which makes the determination of the immunoassay not in real-time and requires trained personnel. Herein, we developed the LC-based immunoassay by using rectangular capillaries as the substrate for immunobinding. The inner surface of rectangular capillaries was decorated with a long alkyl saline, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP), followed by immobilization of human serum albumin (HSA) as the probe. In this situation, the orientation of LC was homeotropic and dark LC image was observed under polarized light. When the solution containing anti-human serum albumin (anti-HSA) were dispensed into the capillary through capillary action, the specific immunobinding between HSA and anti-HSA formed an immunocomplex on the inner surface of capillary, which disrupted the original orientation of LC and led to a dark-to-bright transition of the LC images. The quantification of anti-HSA can be achieved by measuring the length of the bright LC image in the rectangular capillary. By using this immunoassay, the limit of detection (LOD) for anti-HSA is 1 μg/mL, and it did not respond to HSA and anti-human immunoglobulin G (anti-h-IgG). On the other hand, the diversity of the LC-based immunoassay can be extended for HSA detection when we immobilized anti-HSA in the capillary. Because the post-fabrication of LC cell was waived by using rectangular capillaries to develop the LC-based immunoassay, it is more convenient for users to handle and collect more reliable data. Moreover, the results of the immunoassay were visualized through naked-eye and could be recorded by a smartphone; it is more suitable for portable and point-of-care applications.