Ultrasensitive label-free electrochemical immunosensor of NT-proBNP biomarker based on branched AuPd nanocrystals/N-doped honeycombed porous carbon.

N-terminal pro-B-type natriuretic peptide is a major cardiac biomarker for early diagnosis and prognosis of heart failure. Herein, a novel label-free electrochemical immunosensor was developed based on home-made branched AuPd nanocrystals/N-doped porous carbon (AuPd NCS/NPC) for ultrasensitive and high-selective detection of N-terminal pro-B-type natriuretic peptide. Specifically, the AuPd NCS/NPC was prepared by a one-pot wet-chemical strategy by using thymine as a green structural directing agent, whose morphology, structures, and properties were strictly examined, showing high-efficiency catalysis towards electro-reduction of hydrogen peroxide. Under the optimized conditions, the fabricated sensor exhibited a dynamic linear range of 0.001 âˆ¼ 10 ng mL-1 and a low limit of detection (0.34 pg mL-1, S/N = 3) for immunoassay of N-terminal pro-B-type natriuretic peptide. Furthermore, this platform was explored for detection of the biomarker in human serum sample with satisfactory results. Thus, the built biosensor can render valuable guidance for prospective clinical diagnostic applications.

A sandwich-type electrochemical immunosensor for CYFRA 21-1 based on probe-confined in PtPd/polydopamine/hollow carbon spheres coupled with dendritic Au@Rh nanocrystals.

A signal-on sandwich-like electrochemical immunosensor was built for determination of cytokeratin 19 fragments 21-1 (CYFRA 21-1) in non-small cell lung cancer (NSCLC) by confining electroactive dye (e.g., methylene blue, MB) as a probe for amplifying signals. Specifically, core-shell gold@rhodium dendritic nanocrystals (Au@Rh DNCs) behaved as a substrate for primary antibody and accelerate interfacial electron transfer. Besides, hollow carbon spheres (HCSs) were subsequently modified with polydopamine (PDA) and PtPd nanoparticles for sequential integration of the secondary antibody and confinement of MB as a label, termed as MB/PtPd/PDA/HCSs for clarity. The built sensors showed a broad linear range (100 fg mL-1 ~ 100 ng mL-1) for detection of CYFRA 21-1 with an ultra-low detection limit (31.72 fg mL-1, S/N = 3), coupled with satisfactory performance in human serum samples. This work can be explored for assays of other proteins and provides some constructive insights for early and accurate diagnosis of NSCLC.

Growth of Laser-Induced Microbubbles inside Capillary Tubes Affected by Gathered Light-Absorbing Particles.

Microbubbles have important applications in optofluidics. The generation and growth of microbubbles is a complicated process in microfluidic channels. In this paper, we use a laser to irradiate light-absorbing particles to generate microbubbles in capillary tubes and investigate the factors affecting microbubble size. The results show that the key factor is the total area of the light-absorbing particles gathered at the microbubble bottom. The larger the area of the particles at bottom, the larger the size of the microbubbles. Furthermore, the area is related to capillary tube diameter. The larger the diameter of the capillary tube, the more particles gathered at the bottom of the microbubbles. Numerical simulations show that the Marangoni convection is stronger in a capillary tube with a larger diameter, which can gather more particles than that in a capillary tube with a smaller diameter. The calculations show that the particles in contact with the microbubbles will be in a stable position due to the surface tension force.

An approach of bubble generation and manipulation by using the photothermal effects of laser irradiation on light absorbing particles.

The photothermal effects have shown the possibilities for applications in optical manipulation. In this paper, an approach is demonstrated to generate and manipulate a bubble using the photothermal effects. First, a high-power laser is used to irradiate the light absorbing particles for creating a microbubble. The bubble grows up to a diameter of a few hundred micrometers in several seconds due to the diffusion of dissolved gases. The bubble does not float up and is confined at the lower boundary of the sample cell by the thermocapillary force. The force is induced by laser heating of the particles at the bubble base. Second, the bubble can be manipulated following the laser focal spot. The bubble is dragged by the horizontal component of thermocapillary force. The bubble re-grows as it moves because it absorbs the dissolved gases in its migration path. The bubble floats up finally when it grows up to the maximum size. The perpendicular component of thermocapillary force can be estimated equal to the buoyancy of the floated bubble and is about 38 nN at the laser power of 130 mW. Furthermore, we show the generation and manipulation of the bubbles in a capillary. The reason for the decrease in movement velocity in the capillaries has been studied and discussed. The approach of bubble manipulation shows a potential application in transporting the microparticles.

SP1-mediated upregulation of lncRNA LMCD1-AS1 functions a ceRNA for miR-106b-5p to facilitate osteosarcoma progression.

Growing studies have indicated the involvements of long noncoding RNAs (lncRNAs) in the initiation and progression of various tumors. We aimed to investigated the role of lncRNA LMCD1 antisense RNA 1 (LMCD1-AS1) in osteosarcoma development. We found that LMCD1-AS1 and SP1 were highly expressed in osteosarcoma tissues and cell lines. High levels of LMCD1-AS1 were correlated with positively metastasis and poor clinical prognosis. Moreover, we showed that SP1 can bind to the promoter region of LMCD1-AS1, resulting in its overexpression in osteosarcoma. Functionally, silencing of LMCD1-AS1 suppressed the proliferation, migration, invasion and EMT progress of osteosarcoma cells. Mechanistic studies revealed that LMCD1-AS1 was a sponge of miR-106b-5p activity. LMCD1-AS1 modulated survival of osteosarcoma via targeting miR-106b-5p. Overall, we firstly indicated that LMCD1-AS1 overexpression contributes to osteosarcoma development and poor clinical outcome, suggesting that LMCD1-AS1 may be a novel diagnostic and prognostic biomarker for osteosarcoma and a target for osteosarcoma therapy.