An On-Chip Viscoelasticity Sensor for Biological Fluids

Abstract

There are so many non-Newtonian fluids in our daily life, such as milk, blood, cytoplasm, and mucus, most of which are viscoelastic heterogeneous liquid containing cells, inorganic ion, metabolites, and hormones. In microfluidic microparticle-manipulating applications, the target particles are practically distributed within the biological fluids like blood and urine. The viscoelasticity of biological fluid is constantly ignored for simplicity especially when the fluid is substantially diluted and contains rather complex components. However, even the fluid’s ultraweak viscoelasticity actually affects the microparticle migration and may bring a completely different behavior compared with the Newtonian fluids. As a result, a robust and easy operated on-chip viscoelasticity sensor is potential and desired in many research and industrial fields, including assay sample preparation, clinical diagnostics, and on-chip sensor. In this work, we employed stable non-Newtonian fluid–polyethylene oxide (PEO) solutions with various concentrations to investigate and calibrate effects of the weak fluidic viscoelasticity on microparticle behaviors in a double-layered microfluidic channel. An analogy-based database of fluidic patterns for viscoelasticity sensing and relaxation time measurement was established. Then, we tested different biological fluids including blood plasma and fetal bovine serum and proved that they exhibited similar viscoelasticity effects to the PEO solutions with the corresponding concentration, which reached a good agreement with available results by references. The detection limitation of relaxation time can reach 1 ms. It promised a robust and integrated on-chip microfluidic viscoelasticity sensor for different biological fluids without complicated calculations.

Stimuli‐Responsive and Multifunctional Nanogels in Drug Delivery

“…The associated toxicity is oxidative damage to the cells, which can interfere with normal physiological processes by affecting membrane passage or even by penetrating cell membranes. [184] Even though polysaccharide-based nanogels are accepted as an innovational finding in cancer treatment, there are still questions about the safe and effective administration of these nanogels in the human body, several studies claimed that these materials aresatisfactorily efficient and with noobvious toxicities. As most of these experiments wereanimal model based, there is a lack of adequate data from clinical trials in the human body.…”

“…The toxicity arising from the accumulation of carbon in cells and tissues on the application of carbon‐based stimuli‐responsive materials is low when compared to the toxicity brought by heavy metal composition in its surface functionalization. The associated toxicity is oxidative damage to the cells, which can interfere with normal physiological processes by affecting membrane passage or even by penetrating cell membranes [184] …”

Size-Tunable Elasto-Inertial Sorting of Haematococcus pluvialis in the Ultrastretchable Microchannel

“…Preparation of the Elasto-Inertial Medium. Poly-(ethylene oxide) (PEO, 2 MDa; Macklin) was dissolved in deionized (DI) water to prepare a PEO solution with a final concentration of 2000 ppm (ppm), 33 which has excellent biocompatibility (Figure S1). Afterward, the 2000 ppm PEO suspension was mixed with a particle or cell sample at a volume ratio of 1:1 to obtain a final PEO concentration of 1000 ppm.…”

Portable non‐enzymatic electrochemical biosensor based on caffeine for Alzheimer's disease diagnosis

“…Previously, we prepared curcumin 18 and MOF 19 as biometrics to develop Aβ 1–42 ‐specific enzyme‐free sensors, which reduced the cost of the sensor and improved the sensitivity and specificity of the sensor, thus expanding the application of enzyme‐free sensors to a large extent and obtaining a number of patents, providing a new idea for the early diagnosis of AD. However, such non‐enzymatic sensors have some barriers, such as cumbersome characterization of the electrodes, low selectivity to analysts and uncertainty in the mechanism of the sensing process 20 . Specifically, MIPs are susceptible to conformational changes in large biomolecules, which can produce mismatched blotting sites.…”

“…However, such non-enzymatic sensors have some barriers, such as cumbersome characterization of the electrodes, low selectivity to analysts and uncertainty in the mechanism of the sensing process. 20 Specifically, MIPs are susceptible to conformational changes in large biomolecules, which can produce mismatched blotting sites. Furthermore, most metal oxide materials and MOF applied in electrochemical characterization are mainly based on the redox reactions of analysts, which limits the development of the sensor.…”