Nanostructured materials detect epidermal growth factor receptor, neuron specific enolase and carcinoembryonic antigen

An Approach to the Simultaneous Determination of a Panel of Five Biomarkers for the Early Detection of Brain Cancer Using the Stochastic Method

The simultaneous determination of heregulin-α and HER 1–4 plays an important role in brain cancer diagnosis and treatment. To date, only enzyme-linked immunosorbent assay (ELISA) or a semiquantitative colorimetric method have been used for the assay of these biomarkers; these methods are quite expensive and can only determine one biomarker in a run. Four 3D stochastic microsensors based on multi-walled carbon nanotubes enriched with gold nanoparticles and modified with inulin were designed for the simultaneous determination of heregulin-α and HER 1–4 in tumor brain tissue and whole blood samples. For the simultaneous measurement of HRG-α and HER 1–4, all sensors demonstrated low limits of determination (as fg mL−1 magnitude order), high sensitivities, and wide concentration ranges. From biological samples, high recovery values of more than 96% of analytes were obtained. The proposed sensor can detect HER 1–4 and heregulin-α in whole blood and tumor tissue samples at the same time.

Carbon Nanopowder-Based Stochastic Sensor for Ultrasensitive Assay of CA 15-3, CEA and HER2 in Whole Blood

Two microsensors obtained by the physical immobilization of 5,10,15,20-tetraphenyl-21H,23H-porphine (TPP) and 5,10,15,20-tetrakis (pentafluorophenyl chloride)-21H,23H-iron (III) porphyrin (Fe(TPFPP)Cl) in carbon nanopowder decorated with gold nanoparticles (AuNp) were designed, characterized, validated and used for the molecular recognition and simultaneous ultrasensitive determination of CEA, CA15-3 and HER2 in whole blood. High sensitivities were recorded for both microsensors. Low limits of quantification were recorded for all biomarkers: CEA (12.8 pg mL^-1 by using Fe(TPFPP)Cl/AuNp, and 190 fg mL^-1 by using TPP/AuNp), CA 15-3 (100 fU mL^-1 for both microsensors) and HER2 (3.9 fg mL^-1 by using Fe(TPFPP)Cl/AuNp, and 35 fg mL^-1 by using TPP/AuNp). A very good correlation between the results obtained using the proposed microsensors and ELISA, certified by the Student t-test, proves that the screening test can be used for ultrasensitive assays of the three biomarkers in whole blood.

Disposable stochastic sensors for fast analysis of ibuprofen, ketoprofen, and flurbiprofen in their topical pharmaceutical formulations

Three disposable stochastic sensors based on maltodextrin (dextrose equivalent = 4-7) and nanostructures (copper monolayer, carbon monolayer and carbon-copper composite layer) deposited using cold plasma on copy paper were proposed for the fast analysis of ibuprofen, ketoprofen and flurbiprofen in pharmaceutical formulation samples. The widest linear concentration ranges recorded were: for ibuprofen 1 fmol/L - 1 mmol/L when the disposable stochastic sensor based on carbon monolayer was used, for ketoprofen 1 fmol/L - 1 mmol/L when the disposable stochastic sensors based on copper monolayer and carbon-copper composite layer were used, and for flurbiprofen 1 fmol/L - 10 mmol/L when the disposable stochastic sensor based on carbon-copper composite layer was used. The lowest limit of detection recorded for each non-steroidal anti-inflammatory drug was 1 fmol/L.

Diagnostic Value of Imaging Combined With Tumor Markers in Early Detection of Lung Cancer

Objective: The objective of this research is to explore the diagnostic value of imaging plus tumor markers in the early detection of lung cancer. Methods: Sixty patients with lung cancer treated in our hospital from January 2018 to January 2019 were selected as group A. They were matched with 60 patients with benign lung disease as group B and 60 healthy subjects examined in our hospital as group C. The carcino-embryonic antigen (CEA), CYFRA21-1, and neuron-specific enolase (NSE) were assessed, and the diagnostic value of tumor markers plus imaging in lung cancer diagnosis was explored. Results: The CEA, CYFRA21-1, and NSE in group A were evidently superior to those in groups B and C, and those in group B were superior to those in group C (all P < 0.001). CEA had the highest sensitivity (56.7%), and NSE had the highest specificity (93.3%). The tumor markers plus imaging had the highest sensitivity for different types of lung cancer, and the sensitivity to early lung cancer (90%) was superior to other diagnostic methods (P < 0.05). Conclusion: The tumor markers plus imaging is of great significance in early lung cancer diagnosis and provides a reference for judging the pathological classification.

A Silicon Nanowire Array Biosensor Fabricated by Complementary Metal Oxide Semiconductor Technique for Highly Sensitive and Selective Detection of Serum Carcinoembryonic Antigen

In this paper, we present a highly sensitive and selective detection of serum carcinoembryonic antigen (CEA) based on silicon nanowire (SiNW) array device. With the help of traditional microfabrication technology, low-cost and highly controllable SiNW array devices were fabricated. After a series of surface modification processes, SiNW array biosensors show rapid and reliable response to CEA; the detection limit of serum CEA was 10 fg/mL, the current signal is linear with the logarithm of serum CEA concentration in the range of 10 fg/mL to 100 pg/mL. In this work, SiNW array biosensors can obtain strong signal and high signal-to-noise ratio; these advantages can reduce the production cost of the SiNW-based system and promote the application of SiNWs in the field of tumor marker detection.

Soft and flexible material-based affinity sensors

Recent advances in biosensors and point-of-care (PoC) devices are poised to change and expand the delivery of diagnostics from conventional lateral-flow assays and test strips that dominate the market currently, to newly emerging wearable and implantable devices that can provide continuous monitoring. Soft and flexible materials are playing a key role in propelling these trends towards real-time and remote health monitoring. Affinity biosensors have the capability to provide for diagnosis and monitoring of cancerous, cardiovascular, infectious and genetic diseases by the detection of biomarkers using affinity interactions. This review tracks the evolution of affinity sensors from conventional lateral-flow test strips to wearable/implantable devices enabled by soft and flexible materials. Initially, we highlight conventional affinity sensors exploiting membrane and paper materials which have been so successfully applied in point-of-care tests, such as lateral-flow immunoassay strips and emerging microfluidic paper-based devices. We then turn our attention to the multifarious polymer designs that provide both the base materials for sensor designs, such as PDMS, and more advanced functionalised materials that are capable of both recognition and transduction, such as conducting and molecularly imprinted polymers. The subsequent content discusses wearable soft and flexible material-based affinity sensors, classified as flexible and skin-mountable, textile materials-based and contact lens-based affinity sensors. In the final sections, we explore the possibilities for implantable/injectable soft and flexible material-based affinity sensors, including hydrogels, microencapsulated sensors and optical fibers. This area is truly a work in progress and we trust that this review will help pull together the many technological streams that are contributing to the field.

Machine Learning Approach to Enhance the Performance of MNP-Labeled Lateral Flow Immunoassay

The use of magnetic nanoparticle (MNP)-labeled immunochromatography test strips (ICTSs) is very important for point-of-care testing (POCT). However, common diagnostic methods cannot accurately analyze the weak magnetic signal from ICTSs, limiting the applications of POCT. In this study, an ultrasensitive multiplex biosensor was designed to overcome the limitations of capturing and normalization of the weak magnetic signal from MNPs on ICTSs. A machine learning model for sandwich assays was constructed and used to classify weakly positive and negative samples, which significantly enhanced the specificity and sensitivity. The potential clinical application was evaluated by detecting 50 human chorionic gonadotropin (HCG) samples and 59 myocardial infarction serum samples. The quantitative range for HCG was 1-1000 mIU mL^-1 and the ideal detection limit was 0.014 mIU mL^-1, which was well below the clinical threshold. Quantitative detection results of multiplex cardiac markers showed good linear correlations with standard values. The proposed multiplex assay can be readily adapted for identifying other biomolecules and also be used in other applications such as environmental monitoring, food analysis, and national security.

Molecular recognition of pyruvic acid and folic acid in whole blood

Cyclodextrins immobilized in TiO₂Pt–graphene nanocomposite paste simultaneously detect folic and pyruvic acids in whole blood samples.

Use of quantum dot beads-labeled monoclonal antibody to improve the sensitivity of a quantitative and simultaneous immunochromatographic assay for neuron specific enolase and carcinoembryonic antigen

Detection of multiplex tumor markers was of great importance for cancer diagnosis. Immunochromatographic test strip (ICTS) was the most frequently-used point-of-care detection means. Herein, a convenient and fast method for simultaneous quantitative detection of neuron specific enolase (NSE) and carcinoembryonic antigen (CEA) was developed based on ICTS using quantum dot beads (QBs) as marking material. Good monodispersity, high colloidal stability and carboxyl-modified (COOH-) QBs were used. For this method, two test lines were applied to the NC membrane for simultaneous analysis of CEA and NSE respectively. The ideal limit of CEA and NSE detection was 0.0378ng/mL and 0.0426ng/mL with scarcely any cross-reactivity. Moreover, the fluorescent signal intensity of the nitrocellulose membrane could be easily read out in the cooperation of the "Handing" system without professional operators. The possible clinical utilization of this platform was demonstrated by detecting 100 clinic human serums. The result showed that the platform had sensitivity of 99% and 97% for CEA and NSE, while the specificity was 97% and 100% respectively. Our results indicated that the QBs based ICTS not only owning the ability of sensitive and specific simultaneous detection of CEA and NSE, but also showing the potential in developing this ICTS into a routine part of early lung cancer diagnosis.

A novel self-enhanced electrochemiluminescence immunosensor based on hollow Ru-SiO2@PEI nanoparticles for NSE analysis

Poly(ethylenimine) (PEI) and Ru(bpy)3(2+)-doped silica (Ru-SiO2) nanoparticles were simply mixed together to prepare a novel self-enhanced electrochemiluminescence (ECL) composite of Ru-SiO2@PEI. The hollow Ru-SiO2@PEI nanoparticles were used to build an ECL immunosensor for the analysis of neuron specific enolase (NSE). PEI not only assembled on the surface of Ru-SiO2 nanoparticles through the electrostatic interaction to act as co-reactant for Ru(bpy)3(2+) ECL, but also provided alkaline condition to etch the Ru-SiO2 nanoparticles to form the hollow Ru-SiO2@PEI nanoparticles with porous shell. The unique structure of the Ru-SiO2@PEI nanoparticles loaded both a large amount of Ru(bpy)3(2+) and its co-reactant PEI at the same time, which shortened the electron-transfer distance, thereby greatly enhanced the luminous efficiency and amplified the ECL signal. The developed immunosensor showed a wide linear range from 1.0 × 10(-11) to 1.0 × 10(-5) mg mL(-1) with a low detection limit of 1.0 × 10(-11) mg mL(-1) for NSE. When the immunosensor was used for the determination of NSE in clinical human serum, the results were comparable with those obtained by using enzyme-linked immunosorbent assay (ELISA) method. The proposed method provides a promising alternative for NSE analysis in clinical samples.