Electrochemical nano-sensing interface for exosomes analysis and cancer diagnosis.

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Nanotechnology-Enabled Biosensors: A Review of Fundamentals, Design Principles, Materials, and Applications

Electrochemical nano biosensors for the detection of extracellular vesicles exosomes: From the benchtop to everywhere?

Isolating particles from complex fluids is a crucial approach in multiple fields including biomedicine. In particular, biological matrices contain a myriad of distinct particles with different sizes and structures. Extracellular vesicles (EVs), for instance, are nanosized particles carrying vital information from donor to recipient cells, and they have garnered significant impact on disease diagnostics, drug delivery, and theranostics applications. Among all the EV types, exosome particles are one of the smallest entities, sizing from 30 to 100 nm. Separating such small substances from a complex media such as tissue culture and serum is still one of the most challenging steps in this field. Membrane filtration is one of the convenient approaches for these operations; yet clogging, low-recovery, and high fouling are still major obstacles. In this study, we design a two-filter-integrated microfluidic device focusing on dead-end and cross-flow processes at the same time, thereby minimizing any interfering factors on the recovery. The design of this platform is also numerically assessed to understand pressure-drop and flow rate effects over the procedure. As a model, we isolate exosome particles from human embryonic kidney cells cultured in different conditions, which also mimic complex fluids such as serum. Moreover, by altering the flow direction, we refresh the membranes for minimizing clogging issues and benchmark the platform performance for multitime use. By comprehensively analyzing the design and operation parameters of this platform, we address the aforementioned existing barriers in the recovery, clogging, and fouling factors, thereby achieving the use of a microfluidic device multiple times for bio-nanoparticle isolation without any notable issues. 

http://repository.bilkent.edu.tr/bitstream/11693/111581/1/Benchmarking_a_Microfluidic-Based_Filtration_for_Isolating_Biological_Particles.pdf

Benchmarking a Microfluidic-Based Filtration for Isolating Biological Particles

An aptamer-based field-effect transistor (Apta-FET) is a well-developed assay method with high selectivity and sensitivity. Due to the limited information density that natural nucleotide library holds, the Apta-FET faces fundamental restriction in universality to detect various types of analytes. Herein, we demonstrate a type of Apta-FET sensors based on an artificial nucleotide aptamer (AN-Apta-FET). The introduction of an artificial nucleotide increases the diversity of the potential aptamer structure and expands the analyte category of the Apta-FET. The AN-Apta-FET specifically detects hepatoma exosomes, which traditional Apta-FET fails to discriminate from other tumor-derived exosomes, with a limit of detection down to 242 particles mL-1. The AN-Apta-FET distinguishes serum samples of hepatocellular carcinoma patients within 9 min from those of healthy people, showing the potential as a comprehensive assay tool in future disease diagnosis.

Artificial Nucleotide Aptamer-Based Field-Effect Transistor for Ultrasensitive Detection of Hepatoma Exosomes.

Detection of exosomes via an electrochemical biosensor based on C60-Au-Tb composite

Carboxyl porphyrin as signal molecule for sensitive fluorescent detection of aflatoxin B1 via ARGET-ATRP.


 Estrogen receptor alpha (ERα) is an important biomarker for breast cancer, appearing in over 75% of breast cancer cases. In this study, an electrochemical biosensor was constructed for sensitive detection of ERα based on the signal amplification of AuNPs-SWCNT nanocomposites and hemin@HKUST-1. AuNPs-SWCNT was used as a conductive substrate to immobilize the aptamer (Apt) by an Au-S bonding. Then, Apt, ERα, and antibody (Ab) formed a sandwich composite structure through specific recognition and immobilized on the electrode. The hemin@HKUST-1 was introduced into the biosensor via an amide bond with Ab and acted as the signal molecule. AuNPs-SWCNT could significantly enhance the conductivity of the electrode and the large specific surface area of HKUST-1 enabled it to load more hemin, and greatly improved the sensitivity of the biosensor. The detection limit of the biosensor could reach 27.8 fg·mL-1 after optimization of the conditions, with the current intensity and the logarithm of the ERα concentration exhibited a good linear relationship between 100 fg·mL-1 and 100 ng·mL-1. In addition, the biosensor possessed excellent selectivity, stability, reproducibility, and interference immunity. More importantly, it shows great application potential in practical detection.

Highly Sensitive Electrochemical Detection of ERα Based on AuNPs-SWCNT Composites and Hemin@HKUST-1

A novel colorimetric detection of glutathione based on stable free radical TEMPO oxidation of 3,3',5,5'-tetramethylbenzizine (TMB) via Copper(II) acetylacetonate catalysis.

Mengli Wang

Papers

Detection of exosomes via an electrochemical biosensor based on C60-Au-Tb composite

Carboxyl porphyrin as signal molecule for sensitive fluorescent detection of aflatoxin B1 via ARGET-ATRP.

Highly Sensitive Electrochemical Detection of ERα Based on AuNPs-SWCNT Composites and Hemin@HKUST-1

A novel colorimetric detection of glutathione based on stable free radical TEMPO oxidation of 3,3',5,5'-tetramethylbenzizine (TMB) via Copper(II) acetylacetonate catalysis.