The Signal-Enhanced Label-Free Immunosensor Based on Assembly of Prussian Blue-SiO2 Nanocomposite for Amperometric Measurement of Neuron-Specific Enolase

Advances and Challenges in Nanomaterial-Based Electrochemical Immunosensors for Small Cell Lung Cancer Biomarker Neuron-Specific Enolase

Early and rapid detection of neuron-specific enolase (NSE) is highly significant, as it is putative biomarker for small-cell lung cancer as well as COVID-19. Electrochemical techniques have attracted substantial attention for the early detection of cancer biomarkers due to the important properties of simplicity, high sensitivity, specificity, low cost, and point-of-care detection. This work reviews the clinically relevant labeled and label-free electrochemical immunosensors developed so far for the analysis of NSE. The prevailing role of nanostructured materials as electrode matrices is thoroughly discussed. Subsequently, the key performances of various immunoassays are critically evaluated in terms of limit of detection, linear ranges, and incubation time for clinical translation. Electrochemical techniques coupled with screen-printed electrodes developing market level commercialization of NSE sensors is also discussed. Finally, the review concludes with the current challenges associated with available methods and provides a future outlook toward commercialization opportunities for easy detection of NSE.

Advances in point-of-care platforms for traumatic brain injury: recent developments in diagnostics

Traumatic brain injury (TBI) is a major cause of mortality and morbidity, affecting 2 million people annually in the US alone, with direct and indirect costs of $76.3 billion per year. TBI is a progressive disease with no FDA-approved drug for treating patients. Early, accurate and rapid diagnosis can have significant implications for successful triaging and intervention. Unfortunately, current clinical tests for TBI rely on CT scans and MRIs, both of which are expensive, time-consuming, and not accessible to everyone. Recent evidence of biofluid-based biomarkers being released right after a TBI incident has ignited interest in developing point-of-care (POC) platforms for early and on-site TBI diagnosis. These efforts face many challenges to accurate, sensitive, and specific diagnosis and monitoring of TBI. This review includes a deep dive into the latest advances in chemical, mechanical, electrical, and optical sensing systems that hold promise for TBI-POC diagnostic testing platforms. It also focuses on the performance of these proposed biosensors compared to biofluid-based orthodox diagnostic techniques in terms of sensitivity, specificity, and limits of detection. Finally, it examines commercialized TBI-POCs present in the market, the challenges associated with them, and the future directions and prospects of these technologies and the field.

Ultrasensitive electrochemical detection of neuron-specific enolase based on spiny core-shell Au/CuxO@CeO2 nanocubes

As a specific biomarker, neuron-specific enolase (NSE) is an essential clinical indicator for diagnosing small cell lung cancer. In this paper, a sandwich-type electrochemical immunosensor was designed for the quantitative detection of NSE. AuPt nanoblock spherical nanoarchitectonics (AuPt NSNs), a bimetallic nanoparticle with a rugged morphology, were utilized as the substrate, which could enhance the electronic conduction and increase the immobilization capacity of the primary antibody (Ab₁). Moreover, through a simple hydrothermal method, Au/Cu_xO@CeO₂ was prepared as a spiny core-shell nanocube with cerium dioxide (CeO₂) and gold nanoparticles (Au NPs) loading. The combination of Cu₂O, CuO, and CeO₂ showed favorable catalytic activity toward hydrogen peroxide (H₂O₂). Furthermore, the deposition of Au NPs on the spiny surface structure enhanced the specific surface area and biocompatibility, thereby rendering it more effective for loading the second antibody (Ab₂). As the label material, the Au/Cu_xO@CeO₂ achieved signal amplification and sensitive detection with the immunosensor. Under optimal conditions, the designed immunosensor possessed a broad linear range of 50 fg mL^-1 to 100 ng mL^-1 and a limit of detection of 31.3 fg mL^-1, along with satisfactory performance in sensitivity, selectivity, and stability.

Electrochemical biosensors for the detection of lung cancer biomarkers: A review

Cancer is one of the most widespread challenges and important diseases, which has the highest mortality rate. Lung cancer is the most common type of cancer, so that about 25% of all cancer deaths are related to the lung cancer. The lung cancer is classified as two different types with different treatment methodology: the small cell lung carcinoma and nonsmall cell lung carcinoma are two categories of the lung cancer. Since the lung cancer is often in the latent period in its early stages, therefore, early diagnosis of lung cancer has many challenges. Hence, there is a need for sensitive and reliable tools for preclinical diagnosis of lung cancer. Therefore, many detection methods have been employed for early detection of lung cancer. As lung cancer tumors growth in the body, the cancerous cells release numerous DNA, proteins, and metabolites as special biomarkers of the lung cancer. The levels of these biomarkers show the stages of the lung cancer. Therefore, detection of the biomarkers can be used for screening and clinical diagnosis of the lung cancer. There are numerous biomarkers for the lung cancer such as EGFR, CEA, CYFRA 21-1, ENO1, NSE, CA 19-9, CA 125 and VEGF. Nowadays, electrochemical methods are very attractive and useful in the lung cancer detections. So, in this paper, the recent advances and improvements (2010-2018) in the electrochemical detection of the lung cancer biomarkers have been reviewed.

Early detection of lung cancer biomarkers through biosensor technology: A review

Lung cancer is undoubtedly one of the most serious health issues of the 21 st century. It is the second leading cause of cancer-related deaths in both men and women　worldwide, accounting for about 1.5 million deaths annually. Despite advances in the treatment of lung cancer with new pharmaceutical products and technological improvements, morbidity and mortality rates remains a significant challenge for the cancer biologists and oncologists. The vast majority of lung cancer patients present with advanced-stage of pathological process that ultimately leads to poor prognosis and a five-year survival rate less than 20%. Early and accurate screening and analysis using cost-effective means are urgently needed to effectively diagnose the disease, improve the survival rate or to reduce mortality and morbidity associated with lung cancer patients. Thus, the only hope for early recognition of risk factors and timely diagnosis and treatment of lung cancer is biosensors technology. Novel biosensing based diagnostics approaches for predicting metastatic risks are likely to have significant therapeutic and clinical impact in the near future. This article systematically provides a brief overview of various biosensing platforms for identification of lung cancer disease biomarkers, with a specific focus on recent advancements in electrochemical and optical biosensors, analytical performances of different biosensors, challenges and further research opportunities for routine clinical analysis.

Electrochemical Detecting Lung Cancer-Associated Antigen Based on Graphene-Gold Nanocomposite

Using a Au nanoparticle/reduced graphene oxide composite (AuNP-RGO), a signal-enhanced electrochemical immunosensor without label was created to detect neuron-specific enolase (NSE). Furthermore, an environmentally-friendly method was developed to prepare AuNP-RGO by employing chitosan (CS), which served as reducing and stabilizing agent. We showed that the sensitivity of the immunosensor designed in this report was remarkably enhanced because of the numerous active sites in the sensor provided by the AuNP-RGO nanostructure. For the quantification of NSE, the immunosensor exhibited a positive linear relationship with the concentration in the range of 0.1 to 2000 ng/mL, where the limit of the detection was 0.05 ng/mL.

Signal-enhanced electrochemical immunosensor for CD36 based on cascade catalysis of a GOx labeled Prussian blue functionalized Ceria nanohybrid

A novel electrochemical immunosensor was constructed for human scavenger receptor B type CD36 with glucose oxidase labeled Prussian blue nanoparticles functionalized ceria nanoparticles as the signal enhancer.