Ratiometric Multicolor Analysis of Intracellular MicroRNA Using a Chain Hybrid Substitution-Triggered Self-Assembly of Silver Nanocluster-Based Label-Free Sensing Platform

2019 ◽  
Vol 12 (1) ◽  
pp. 373-379 ◽  
Author(s):  
Shenghao Xu ◽  
Liping Jiang ◽  
Jun Wang ◽  
Yuhuan Gao ◽  
Xiliang Luo
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Valente

AbstractImitating the transition from inanimate to living matter is a longstanding challenge. Artificial life has achieved computer programs that self-replicate, mutate, compete and evolve, but lacks self-organized hardwares akin to the self-assembly of the first living cells. Nonequilibrium thermodynamics has achieved lifelike self-organization in diverse physical systems, but has not yet met the open-ended evolution of living organisms. Here, I look for the emergence of an artificial-life code in a nonequilibrium physical system undergoing self-organization. I devise a toy model where the onset of self-replication of a quantum artificial organism (a chain of lambda systems) is owing to single-photon pulses added to a zero-temperature environment. I find that spontaneous mutations during self-replication are unavoidable in this model, due to rare but finite absorption of off-resonant photons. I also show that the replication probability is proportional to the absorbed work from the photon, thereby fulfilling a dissipative adaptation (a thermodynamic mechanism underlying lifelike self-organization). These results hint at self-replication as the scenario where dissipative adaptation (pointing towards convergence) coexists with open-ended evolution (pointing towards divergence).


Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 33
Author(s):  
Han Yan ◽  
Zhen Zhang ◽  
Ting Weng ◽  
Libo Zhu ◽  
Pang Zhang ◽  
...  

Nanopores have a unique advantage for detecting biomolecules in a label-free fashion, such as DNA that can be synthesized into specific structures to perform computations. This method has been considered for the detection of diseased molecules. Here, we propose a novel marker molecule detection method based on DNA logic gate by deciphering a variable DNA tetrahedron structure using a nanopore. We designed two types of probes containing a tetrahedron and a single-strand DNA tail which paired with different parts of the target molecule. In the presence of the target, the two probes formed a double tetrahedron structure. As translocation of the single and the double tetrahedron structures under bias voltage produced different blockage signals, the events could be assigned into four different operations, i.e., (0, 0), (0, 1), (1, 0), (1, 1), according to the predefined structure by logic gate. The pattern signal produced by the AND operation is obviously different from the signal of the other three operations. This pattern recognition method has been differentiated from simple detection methods based on DNA self-assembly and nanopore technologies.


Author(s):  
Dominic Vella ◽  
Emmanuel du Pontavice ◽  
Cameron L. Hall ◽  
Alain Goriely

Spherical neodymium–iron–boron magnets are permanent magnets that can be assembled into a variety of structures owing to their high magnetic strength. A one-dimensional chain of these magnets responds to mechanical loadings in a manner reminiscent of an elastic rod. We investigate the macroscopic mechanical properties of assemblies of ferromagnetic spheres by considering chains, rings and chiral cylinders of magnets. Based on energy estimates and simple experiments, we introduce an effective magnetic bending stiffness for a chain of magnets and show that, used in conjunction with classic results for elastic rods, it provides excellent estimates for the buckling and vibration dynamics of magnetic chains. We then use this estimate to understand the dynamic self-assembly of a cylinder from an initially straight chain of magnets.


RSC Advances ◽  
2016 ◽  
Vol 6 (62) ◽  
pp. 57502-57506 ◽  
Author(s):  
Lin Liu ◽  
Qing Li ◽  
Li-Juan Tang ◽  
Ru-Qin Yu ◽  
Jian-Hui Jiang

A hybridization chain reaction (HCR) lightened by DNA-stabilized silver nanoclusters (AgNCs) as a label-free and turn on fluorescence platform for nucleic acid assays.


Talanta ◽  
2019 ◽  
Vol 195 ◽  
pp. 306-312 ◽  
Author(s):  
Peng Lei ◽  
Ying Zhou ◽  
Guomei Zhang ◽  
Yan Zhang ◽  
Caihong Zhang ◽  
...  

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 98 ◽  
Author(s):  
Ngoc-Viet Nguyen ◽  
Chun-Hao Yang ◽  
Chung-Jung Liu ◽  
Chao-Hung Kuo ◽  
Deng-Chyang Wu ◽  
...  

Improvement of methods for reliable and early diagnosis of the cellular diseases is necessary. A biological selectivity probe, such as an aptamer, is one of the candidate recognition layers that can be used to detect important biomolecules. Lung cancer is currently a typical cause of cancer-related deaths. In this work, an electrical sensing platform is built based on amine-terminated aptamer modified-gold electrodes for the specific, label-free detection of a human lung carcinoma cell line (A549). The microdevice, that includes a coplanar electrodes configuration and a simple microfluidic channel on a glass substrate, is fabricated using standard photolithography and cast molding techniques. A procedure of self-assembly onto the gold surface is proposed. Optical microscope observations and electrical impedance spectroscopy measurements confirm that the fabricated microchip can specifically and effectively identify A549 cells. In the experiments, the capacitance element that is dominant in the change of the impedance is calculated at the appropriate frequency for evaluation of the sensitivity of the biosensor. Therefore, a simple, inexpensive, biocompatible, and selective biosensor that has the potential to detect early-stage lung cancer would be developed.


RSC Advances ◽  
2015 ◽  
Vol 5 (70) ◽  
pp. 56583-56589 ◽  
Author(s):  
Yulan Wang ◽  
Dan Wu ◽  
Yong Zhang ◽  
Xiang Ren ◽  
Yaoguang Wang ◽  
...  

In this work, a novel and ultrasensitive label-free electrochemical immunosensor was developed for the quantitative detection of alpha fetoprotein (AFP).


RSC Advances ◽  
2017 ◽  
Vol 7 (43) ◽  
pp. 26930-26934 ◽  
Author(s):  
Wei Liu ◽  
Huanhuan Li ◽  
Yanli Wei ◽  
Chuan Dong

A label-free phosphorescence strategy to determine trypsin was proposed using Mn-ZnS QDs as the phosphorescence probe with a better validity.


Sign in / Sign up

Export Citation Format

Share Document